Pin goimports in pre-commit to v0.30.0 for Go 1.22 compat (#4160)

After pinning actions/setup-go to v6.4.0, the reusable-pre-commit job
runs with GOTOOLCHAIN=local (the v6 default). pre-commit installs the
Lint hook's `goimports@latest`, which now resolves to
golang.org/x/tools@v0.45.0 and requires Go >= 1.25 — install fails
under Go 1.22.12 with GOTOOLCHAIN=local, leaving generated files
un-formatted and breaking the Generate hook.

v0.30.0 is the last golang.org/x/tools release whose go.mod still
declares `go 1.22.0`; v0.31.0+ require Go 1.23+. Pinning here keeps
the pre-commit job honest on the declared 1.22.x toolchain instead of
silently auto-upgrading via GOTOOLCHAIN=auto, and bounds the blast
radius of future tools releases.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: jack-edmonds-dd

.pre-commit-config.yaml

@@ -16,7 +16,7 @@ repos:
     # types: ["file", "go"]
     pass_filenames: false
     additional_dependencies:
-      - golang.org/x/tools/cmd/goimports@latest
+      - golang.org/x/tools/cmd/goimports@v0.30.0
   - id: generate-doc
     name: Doc generation
     stages: [manual]