Fix mypy regex

[kylebarron]

There's (now) a colon after the filepath. I also had to use --show-absolute-path when calling mypy.

[marian-code]

Yes, I am too seeing a colon now. Thanks for fixing this.

As for the --show-absolute-path I am not seeing any problem with that. Here is an excerpt of GH action output.

Running: mypy --ignore-missing-imports --follow-imports=silent --show-column-numbers ./tests/__init__.py ./tests/test_python_code.py ./tests/subtest/subtest_python_code.py
Error: tests/subtest/subtest_python_code.py:5:8: error: invalid syntax
Found 1 error in 1 file (errors prevented further checking)
mypy error

Just to be clear, without --show-absolute-path it does not work for you? or is the problem that you just want to see the absolute path?

[kylebarron]

I am not seeing any problem with that

Sorry that was a false alarm. I didn't use this action as-is, since I already had a CI setup and didn't want to change how the tests were actually run I just copied the matchers/*.json and looked at entrypoint.sh for necessary flags for each command. I was integrating the tests into a monorepo setup, where the tests aren't run at the repo root, but rather inside multiple subdirectories. I think because of that, the relative paths shown by mypy didn't match the repo's paths, and it didn't work.

So I don't have any evidence of your snippet above not working.

[marian-code]

OK, I am merging this.