Fix: update ASN regex to support Unicode

[eukub]

Proposed change

fixed regular expression to support Unicode and improve readability

Closes #(issue or discussion)

• Bug fix: non-breaking change which fixes an issue.
• New feature: non-breaking change which adds functionality. Please read the important note above.
• Breaking change: fix or feature that would cause existing functionality to not work as expected.
• Documentation only.
• Other. Please explain:
  fixed regular expression to support Unicode and improve readability

Checklist:

• I have read & agree with the contributing guidelines.
• If applicable, I have included testing coverage for new code in this PR, for backend and / or front-end changes.
• If applicable, I have tested my code for new features & regressions on both mobile & desktop devices, using the latest version of major browsers.
• If applicable, I have checked that all tests pass, see documentation.
• I have run all pre-commit hooks, see documentation.
• I have made corresponding changes to the documentation as needed.
• I have checked my modifications for any breaking changes.

[paperless-ngx-secretary]

Hello @eukub,

thank you very much for submitting this PR to us!

This is what will happen next:

1. My robotic colleagues will check your changes to see if they break anything. You can see the progress below.
2. Once that is finished, human contributors from paperless-ngx review your changes. Since this seems to be a small change, only a single contributor has to review your changes.
3. Please improve anything that comes up during the review until your pull request gets approved.
4. Your pull request will be merged into the dev branch. Changes there will be tested further.
5. Eventually, changes from you and other contributors will be merged into main and a new release will be made.

Please allow up to 7 days for an initial review. We're all very excited about new pull requests but we only do this as a hobby.
If any action will be required by you, please reply within a month.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (74e89b0) 96.21% compared to head (408dfc1) 96.21%.

Additional details and impacted files

@@           Coverage Diff           @@
##              dev    #5099   +/-   ##
=======================================
  Coverage   96.21%   96.21%           
=======================================
  Files         382      382           
  Lines       14694    14694           
  Branches     1160     1160           
=======================================
  Hits        14138    14138           
  Misses        552      552           
  Partials        4        4           

Flag	Coverage Δ
backend	94.79% <100.00%> (ø)
frontend	97.84% <ø> (ø)

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[github-actions]

This pull request has been automatically locked since there has not been any recent activity after it was closed. Please open a new discussion or issue for related concerns.