Limit "single source file per target" presubmit to check only python …

…targets.

Add path exclusions for certain directories.

PiperOrigin-RevId: 586378455

tensorflow/build_cleaner_spec.textproto

@@ -1,12 +1,12 @@
 # proto-file: devtools/build_cleaner/proto/actions.proto
 # proto-message: ActionSpecs
 
-# Rules (except for the allowlist) should not have more than one source file.
+# Python rules should not have more than one source file.
 action_spec {
   action: CHECK_FILE_COUNT
   file_count_params {
     rule_selector {
-      rule_kind_regex: "^(?!filegroup|genrule|_policy_filegroup).*$"
+      rule_kind_regex: "^.*py(type)?(_strict)?_(binary|library|test).*$"
       generator_function_regex: "^(?!boq_header)$"
     }
     max_source_count: 1