ci(renovate): update Go import paths on major bumps (#37641)

Enable `gomodUpdateImportPaths` so Renovate rewrites import paths (e.g.
`foo/v2` → `foo/v3`) across the repo when bumping Go modules across
major versions.

---
This PR was written with the help of Claude Opus 4.7

Co-authored-by: Claude (Opus 4.7) <noreply@anthropic.com>
Co-authored-by: Nicolas <bircni@icloud.com>

renovate.json5

@@ -61,6 +61,7 @@
     {
       "groupName": "go dependencies",
       "matchManagers": ["gomod"],
+      "postUpdateOptions": ["gomodUpdateImportPaths"],
       "postUpgradeTasks": {
         "commands": ["make tidy"],
         "fileFilters": ["go.mod", "go.sum", "assets/go-licenses.json"],