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

tests/integration/api_packages_alpine_test.go

@@ -480,7 +480,6 @@ aiIK5QoSDwAAAAAAAAAAAAAAAP/IK49O1e8AKAAA`
 					req = NewRequest(t, "DELETE", fmt.Sprintf("%s/%s/%s/x86_64/%s-%s.apk", rootURL, branch, repository, pkg, packageVersion)).
 						AddBasicAuth(user.Name)
 					MakeRequest(t, req, http.StatusNoContent)
-
 				}
 				// Deleting the last file of an architecture should remove that index
 				req := NewRequest(t, "GET", fmt.Sprintf("%s/%s/%s/x86_64/APKINDEX.tar.gz", rootURL, branch, repository))