fix(precompile): skip precompilation for directory and pyc inputs in srcs - #4113

Directories and precompiled pyc files cannot be compiled directly into pyc files. Skip precompiling when src.is_directory is true or the extension is pyc/pyo while retaining them in target outputs.

… srcs

Allow arbitrary files in the srcs attribute while filtering to Python source files via an is_py_source helper. Skip precompilation for directories or any file that is not a Python source file, and remove legacy py3 extension references.

…mat srcs doc

Propagate input .pyc files through precompilation into target default outputs, and format the srcs attribute docstring with a list of allowed file types.

…ies to maybe_precompile

Compute direct_sources as the py, pyc, and directory files from srcs, pass direct_sources to maybe_precompile, and update tree artifact analysis test outputs.

…ecompile doc

Factor out filter_to_direct_sources helper in common.bzl to share direct sources filtering across py_library and py_executable, and update _precompile return type docstring.

…_errors

…bzl_library dep

Add news fragment for skip precompile src errors fix, document allowed srcs file types with versionchanged in attributes.bzl, and add :common dependency to precompile bzl_library.

Associate news entry with newly created PR bazel-contrib#4113.

…ctive

Update version directive in attributes.bzl from VERSION_NEXT_FEATURE to VERSION_NEXT_PATCH.

…ntry

Update news/4113.fixed.md to use valid Sphinx MyST {obj} syntax, wrap lines within 80 columns, and link to PR bazel-contrib#4113.

… skip_precompile_src_errors