Upgrade dependencies, pivot to crypto/sha256 for FIPS 140 compliance

[CascadingRadium]

• Remove legacy vendor directory
• Upgrade dependencies - bits-and-blooms/bitset, blevesearch/mmap-go, spf13/cobra
  • Requires: Merge edsrzf/mmap-go@v1.2.0 into blevesearch/mmap-go@master mmap-go#6
• Fix README badges
• Replace crypto/md5 with crypto/sha256 for FIPS 140 compatibility (Replace MD5 with SHA-256 for FIPS 140 compatibility #26)

[Copilot]

Pull request overview

This PR upgrades project dependencies and performs maintenance tasks including removing legacy code, updating Go version, and fixing repository references.

Changes:

• Updated Go version from 1.21 to 1.24.0 and upgraded all dependencies
• Added modern //go:build directives alongside legacy +build tags
• Fixed README badges to reflect repository move from couchbase to blevesearch organization

Reviewed changes

Copilot reviewed 7 out of 427 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
go.mod	Updated Go version to 1.24.0 and upgraded all dependencies to latest versions
vellum_nommap.go	Added modern //go:build nommap directive for build constraints
vellum_mmap.go	Added modern //go:build !nommap directive for build constraints
vellum.go	Removed trailing empty line from package documentation
levenshtein/levenshtein_nfa.go	Converted triple-slash comments to standard Go double-slash format
builder.go	Converted ASCII art diagram from line comments to block comment format
README.md	Updated badge URLs to reference blevesearch organization instead of couchbase

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[Copilot]

Pull request overview

Copilot reviewed 8 out of 428 changed files in this pull request and generated no new comments.

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[Copilot]

Pull request overview

Copilot reviewed 8 out of 428 changed files in this pull request and generated no new comments.

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[abhinavdangeti]

@CascadingRadium Can you confirm the vendor directory was basically unused since we introduced go.mod?

[CascadingRadium]

Hi @abhinavdangeti, the vendor directory basically copies all the dependencies into the repo. Any dependency upgrade, followed by go mod tidy, would require running go mod vendor to keep the vendor files in sync.

Considering the fact that vellum is used as a dependency by zapx and others, the vendor files are basically unused, since zapx, bleve, and any upstream repo will look for vendor files in their own repositories.

In short, yes—the vendor files are an artifact of the pre–Go modules era and can be safely removed.

[abhinavdangeti]

This one comes with v1.2.0.