Fix Vulkan docker build failure on Ubuntu 26.04

[Copilot]

Make sure to read the contributing guidelines before submitting a PR

Vulkan docker build fails on Ubuntu 26.04 because numpy has no pre-built wheel and pip falls back to source compilation, which requires a C compiler not present in the "full" stage.

Error from failed builds:

Running `gcc --version` gave "[Errno 2] No such file or directory: 'gcc'"

Fix: Add build-essential to the "full" stage apt-get install to provide gcc for source compilation of Python packages.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Misc. bug: Vulkan docker build fails on github actions</issue_title>
<issue_description>### Name and Version

Version 7134

Operating systems

Linux

Which llama.cpp modules do you know to be affected?

Other (Please specify in the next section)

Command line

Problem description & steps to reproduce

Hello again! Last week I opened an issue concerning an issue with the vulkan docker build. The issue was resolved with this commit, thank you btw :). The fix was to update the ubuntu version with which the dockerfile was built. Since that commit, docker builds of the vulkan image have been failing on github actions. A quick glance at the error logs from the first unsuccessful build shows that numpy fails to build, most likely due to a missing C compiler. Given that ubuntu 26.04 has not been released yet, there may be a conflict with the build essentials used in the dockerfile.

Paging @ericcurtin as it seems relevant.

First Bad Commit

The first bad commit is the one that introduced the fix to the issue I opened previously, commit bc809e9.

Relevant log output

ggml-org/llama.cpp#20 13.48   Downloading numpy-1.26.4.tar.gz (15.8 MB)
ggml-org/llama.cpp#20 13.61      ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 15.8/15.8 MB 135.0 MB/s eta 0:00:00
ggml-org/llama.cpp#20 15.54   Installing build dependencies: started
ggml-org/llama.cpp#20 17.26   Installing build dependencies: finished with status 'done'
ggml-org/llama.cpp#20 17.26   Getting requirements to build wheel: started
ggml-org/llama.cpp#20 17.39   Getting requirements to build wheel: finished with status 'done'
ggml-org/llama.cpp#20 17.39   Installing backend dependencies: started
ggml-org/llama.cpp#20 18.38   Installing backend dependencies: finished with status 'done'
ggml-org/llama.cpp#20 18.38   Preparing metadata (pyproject.toml): started
ggml-org/llama.cpp#20 19.21   Preparing metadata (pyproject.toml): finished with status 'error'
ggml-org/llama.cpp#20 19.22   error: subprocess-exited-with-error
ggml-org/llama.cpp#20 19.22   
ggml-org/llama.cpp#20 19.22   × Preparing metadata (pyproject.toml) did not run successfully.
ggml-org/llama.cpp#20 19.22   │ exit code: 1
ggml-org/llama.cpp#20 19.22   ╰─> [20 lines of output]
ggml-org/llama.cpp#20 19.22       + /usr/bin/python3 /tmp/pip-install-p4xgmo1y/numpy_ba63b7775fd142ee9f0f697015a2f2d0/vendored-meson/meson/meson.py setup /tmp/pip-install-p4xgmo1y/numpy_ba63b7775fd142ee9f0f697015a2f2d0 /tmp/pip-install-p4xgmo1y/numpy_ba63b7775fd142ee9f0f697015a2f2d0/.mesonpy-19k9xnsx -Dbuildtype=release -Db_ndebug=if-release -Db_vscrt=md --native-file=/tmp/pip-install-p4xgmo1y/numpy_ba63b7775fd142ee9f0f697015a2f2d0/.mesonpy-19k9xnsx/meson-python-native-file.ini
ggml-org/llama.cpp#20 19.22       The Meson build system
ggml-org/llama.cpp#20 19.22       Version: 1.2.99
ggml-org/llama.cpp#20 19.22       Source dir: /tmp/pip-install-p4xgmo1y/numpy_ba63b7775fd142ee9f0f697015a2f2d0
ggml-org/llama.cpp#20 19.22       Build dir: /tmp/pip-install-p4xgmo1y/numpy_ba63b7775fd142ee9f0f697015a2f2d0/.mesonpy-19k9xnsx
ggml-org/llama.cpp#20 19.22       Build type: native build
ggml-org/llama.cpp#20 19.22       Project name: NumPy
ggml-org/llama.cpp#20 19.22       Project version: 1.26.4
ggml-org/llama.cpp#20 19.22       
ggml-org/llama.cpp#20 19.22       ../meson.build:1:0: ERROR: Unknown compiler(s): [['cc'], ['gcc'], ['clang'], ['nvc'], ['pgcc'], ['icc'], ['icx']]
ggml-org/llama.cpp#20 19.22       The following exception(s) were encountered:
ggml-org/llama.cpp#20 19.22       Running `cc --version` gave "[Errno 2] No such file or directory: 'cc'"
ggml-org/llama.cpp#20 19.22       Running `gcc --version` gave "[Errno 2] No such file or directory: 'gcc'"
ggml-org/llama.cpp#20 19.22       Running `clang --version` gave "[Errno 2] No such file or directory: 'clang'"
ggml-org/llama.cpp#20 19.22       Running `nvc --version` gave "[Errno 2] No such file or directory: 'nvc'"
ggml-org/llama.cpp#20 19.22       Running `pgcc --version` gave "[Errno 2] No such file or directory: 'pgcc'"
ggml-org/llama.cpp#20 19.22       Running `icc --version` gave "[Errno 2] No such file or directory: 'icc'"
ggml-org/llama.cpp#20 19.22       Running `icx --version` gave "[Errno 2] No such file or directory: 'icx'"
ggml-org/llama.cpp#20 19.22       
ggml-org/llama.cpp#20 19.22       A full log can be found at /tmp/pip-install-p4xgmo1y/numpy_ba63b7775fd142ee9f0f697015a2f2d0/.mesonpy-19k9xnsx/meson-logs/meson-log.txt
ggml-org/llama.cpp#20 19.22       [end of output]
ggml-org/llama.cpp#20 19.22   
ggml-org/llama.cpp#20 19.22   note: This error originates from a subprocess, and is lik...

</details>

- Fixes ggml-org/llama.cpp#17522

<!-- START COPILOT CODING AGENT TIPS -->
---

💡 You can make Copilot smarter by setting up custom instructions, customizing its development environment and configuring Model Context Protocol (MCP) servers. Learn more [Copilot coding agent tips](https://gh.io/copilot-coding-agent-tips) in the docs.