auto_version: skip non-publishable go.mod modules

[yanyi-wego]

Summary

• auto_version now reads the module … line from each go.mod and only tags directories whose declared path equals github.com/wego/pkg/<relative-dir>. Anything else is skipped with a reason.
• Fixes the recent erroneous tagging of linters/isolint/testdata/v0.1.0, linters/isolint/testdata/v0.1.1, and linters/stringlint/testdata/v0.1.0. Those directories are standalone Go modules only because golang.org/x/tools/go/analysis/analysistest requires fixtures to be a self-contained module, and they declare module example — they are not meant for consumption.
• Cleanup of the already-pushed bad tags is not part of this PR. Doing it separately so the destructive git push :refs/tags/... is reviewed on its own.

Why module-path matching (and not the alternatives)

Option	How it would work	Why rejected
Path filter */testdata/*	find … -not -path '*/testdata/*'	Only covers the testdata convention. Misses any future auxiliary go.mod — examples/, benchmarks/, cmd/playground/, etc. Hardcodes one naming convention into the release tooling.
Marker file (.no-release / .tagignore)	Opt-out per directory	New convention to teach. Easy to forget when adding another linter; the failure mode is silent (a stray release tag).
Allow-list in script	Hardcode the publishable dirs	Every new package edits the script. Forgetting it means the package never gets tagged — silent failure in the other direction.
Module-path check (chosen)	Require go.mod's module … line to equal github.com/wego/pkg/<dir>; skip with a logged reason otherwise	See below.

Why this is cleaner and scales

• It tests the actual property we care about. The release tooling's job is to publish wego/pkg modules. The truthful question is "does this go.mod declare itself as part of github.com/wego/pkg?" Module path matching answers that directly; every other option is a proxy.
• No new convention. It piggybacks on the module directive that go.mod files already have. Nothing new for contributors to remember.
• Auto-handles every current and future case. Linter testdata today, more linter fixtures tomorrow, example modules, benchmark harnesses — all handled without script changes, because none of them will declare a github.com/wego/pkg/... module path.
• Self-documenting failure mode. When something is skipped, the script logs skipping <pkg> (module path "X" is not "Y"). If a real package is misconfigured, the mismatch is loud and immediately diagnosable.
• Works at any nesting depth. The check concatenates module_root + relative dir, so iso/site, http/middleware, linters/isolint, and any future a/b/c resolve identically — no special casing.

Verification

Dry-run against every go.mod in the repo classified all 33 publishable modules as TAG and both linter testdata fixtures as SKIP with the expected reason.

• Separately (not in this PR) clean up the existing bad remote tags: linters/isolint/testdata/v0.1.0, linters/isolint/testdata/v0.1.1, linters/stringlint/testdata/v0.1.0.

🤖 Generated with Claude Code