build(deps): bump golangci/golangci-lint-action from 4 to 6

Bumps [golangci/golangci-lint-action](https://github.com/golangci/golangci-lint-action) from 4 to 6.
- [Release notes](https://github.com/golangci/golangci-lint-action/releases)
- [Commits](golangci/golangci-lint-action@v4...v6)

---
updated-dependencies:
- dependency-name: golangci/golangci-lint-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/validate.yml

@@ -35,7 +35,7 @@ jobs:
         with:
           go-version: 1.22.x
           cache: false # golangci-lint-action does its own caching
-      - uses: golangci/golangci-lint-action@v4
+      - uses: golangci/golangci-lint-action@v6
         with:
           version: v1.56
 
@@ -64,7 +64,7 @@ jobs:
         with:
           go-version: 1.22.x
           cache: false # golangci-lint-action does its own caching
-      - uses: golangci/golangci-lint-action@v4
+      - uses: golangci/golangci-lint-action@v6
         with:
           version: v1.56
       - name: test-stubs