ci: integration test times out when another one is busy

[Jakob-Naucke]

Seen on #199. The integration tests time out after 2h, but are forced to run in sequence, so it'll time out because most of the time was spent waiting for another one.

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Step 6/8: Acquiring exclusive lock on Beaker machine
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[INFO] Lock file: /tmp/tec-operator-ci.lock
[INFO] Lock holder ID: ci-op-8s545qdp-2023670978252378112-1771315870
[INFO] Lock timeout: 21600 seconds (6 hours)
[INFO] This ensures only one CI job runs on the Beaker machine at a time
[INFO] Transferring lock holder script to Beaker machine...
[INFO] Starting lock holder process on Beaker machine...
[INFO] Acquiring lock (timeout: 21600s / 6 hours)...
[INFO] Waiting for lock holder process to acquire lock or timeout...
[INFO] This may take up to 21600 seconds if another job is running...
[INFO] Still waiting for lock... (currently held by: ci-op-vxv5z98h-2023671078945034240-1771315870)
… [same line, many times] …
[INFO] Still waiting for lock... (currently held by: ci-op-vxv5z98h-2023671078945034240-1771315870)
{"component":"entrypoint","file":"sigs.k8s.io/prow/pkg/entrypoint/run.go:169","func":"sigs.k8s.io/prow/pkg/entrypoint.Options.ExecuteProcess","level":"error","msg":"Process did not finish before 2h0m0s timeout","severity":"error","time":"2026-02-17T10:11:04Z"}
{"component":"entrypoint","file":"sigs.k8s.io/prow/pkg/entrypoint/run.go:264","func":"sigs.k8s.io/prow/pkg/entrypoint.gracefullyTerminate","level":"error","msg":"Process gracefully exited before 5m0s grace period","severity":"error","time":"2026-02-17T10:11:06Z"}
{"component":"entrypoint","error":"process timed out","file":"sigs.k8s.io/prow/pkg/entrypoint/run.go:84","func":"sigs.k8s.io/prow/pkg/entrypoint.Options.internalRun","level":"error","msg":"Error executing test process","severity":"error","time":"2026-02-17T10:11:06Z"}
error: failed to execute wrapped command: exit status 127 
�[36mINFO�[0m[2026-02-17T10:11:07Z] Step operator-lifecycle-verify-trusted-execution-clusters-ref-operator-beaker-kind-provision failed after 2h0m59s.