feat: migrate from GitLab CI to Gitea Actions

- Update git remote to git.unbound.se
- Add Gitea workflows: ci.yaml, pre-commit.yaml, release.yaml, goreleaser.yaml
- Delete .gitlab-ci.yml
- Update Go module path to gitea.unbound.se/unboundsoftware/schemas
- Update all imports to new module path
- Update Docker registry to oci.unbound.se
- Update .goreleaser.yml for Gitea releases with internal cluster URL
- Remove GitLab CI linter from pre-commit config
- Use shared release workflow with tag_only for versioning

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.goreleaser.yml

@@ -21,6 +21,9 @@ homebrew_casks:
   repository:
     owner: unboundsoftware
     name: homebrew-taps
+    git:
+      url: 'http://gitea-http.gitea.svc.cluster.local:3000/unboundsoftware/homebrew-taps.git'
+      token: '{{ .Env.GITEA_TOKEN }}'
   binaries: [schemactl]
   directory: Casks
   commit_author:
@@ -32,6 +35,7 @@ homebrew_casks:
       install: |
         # replace foo with the actual binary name
         system_command "/usr/bin/xattr", args: ["-dr", "com.apple.quarantine", "#{staged_path}/schemactl"]
+  url_template: "https://git.unbound.se/unboundsoftware/schemas/releases/download/{{ .Tag }}/{{ .ArtifactName }}"
 
 archives:
 - id: unbound-schemas