SPDX warnings in Regexp

[SebastianSchildt]

I noticed the code gives warnings on the pattern machers:

/home/runner/work/_actions/eclipse-kuksa/kuksa-actions/4/spdx//verify-spdx-headers:11: SyntaxWarning: invalid escape sequence '\s'
  SPDX = re.compile(f'SPDX-License-Identifier:\s+({SLUG.pattern})')
/home/runner/work/_actions/eclipse-kuksa/kuksa-actions/4/spdx//verify-spdx-headers:24: SyntaxWarning: invalid escape sequence '\s'
  pattern = f"^{init}\s*{SPDX.pattern}\s*{fini}\s*$"
/home/runner/work/_actions/eclipse-kuksa/kuksa-actions/4/spdx//verify-spdx-headers:24: SyntaxWarning: invalid escape sequence '\s'
  pattern = f"^{init}\s*{SPDX.pattern}\s*{fini}\s*$"
/home/runner/work/_actions/eclipse-kuksa/kuksa-actions/4/spdx//verify-spdx-headers:24: SyntaxWarning: invalid escape sequence '\s'
  pattern = f"^{init}\s*{SPDX.pattern}\s*{fini}\s*$"
1 will be accepted!

(see e.g. https://github.com/COVESA/Open1722/actions/runs/12976294699/job/36188380910?pr=76 )

Still seems to work, did not yet look deeper. @erikbosch Have you maybe seen this before? is it new? Expected? Bad?

[erikbosch]

I assume this is related to the recent "auto-upgrade" to Ubuntu 24.04 when using ubuntu-latest (at the moment it seems to be a bit random if you get 22.04 or 24.04). That gives us Python 3.12 (or newer?) and a changed handling for escapes.

https://docs.python.org/dev/whatsnew/3.12.html#other-language-changes

I changed to using raw strings in #17. That seems to the trick

[SebastianSchildt]

Fixed in #17