Enable more revive linter rules (#30608)

Noteable additions:

- `redefines-builtin-id` forbid variable names that shadow go builtins
- `empty-lines` remove unnecessary empty lines that `gofumpt` does not
remove for some reason
- `superfluous-else` eliminate more superfluous `else` branches

Rules are also sorted alphabetically and I cleaned up various parts of
`.golangci.yml`.

(cherry picked from commit 74f0c84fa4245a20ce6fb87dac1faf2aeeded2a2)

Conflicts:
	.golangci.yml
	apply the linter recommendations to Forgejo code as well

modules/indexer/code/bleve/bleve.go

@@ -193,7 +193,6 @@ func (b *Indexer) addDelete(filename string, repo *repo_model.Repository, batch
 func (b *Indexer) Index(ctx context.Context, repo *repo_model.Repository, sha string, changes *internal.RepoChanges) error {
 	batch := inner_bleve.NewFlushingBatch(b.inner.Indexer, maxBatchSize)
 	if len(changes.Updates) > 0 {
-
 		// Now because of some insanity with git cat-file not immediately failing if not run in a valid git directory we need to run git rev-parse first!
 		if err := git.EnsureValidGitRepository(ctx, repo.RepoPath()); err != nil {
 			log.Error("Unable to open git repo: %s for %-v: %v", repo.RepoPath(), repo, err)
@@ -337,7 +336,6 @@ func (b *Indexer) Search(ctx context.Context, opts *internal.SearchOptions) (int
 		if result, err = b.inner.Indexer.Search(facetRequest); err != nil {
 			return 0, nil, nil, err
 		}
-
 	}
 	languagesFacet := result.Facets["languages"]
 	for _, term := range languagesFacet.Terms.Terms() {