Fix PGPy/sectxt parser

[bwbroersma]

• See upstream issue Certain security.txt files can cause parser to hang indefinitely DigitalTrustCenter/sectxt#74

This is solved by either pinning sectxt to PR:

• Require PGPy pull request 467 DigitalTrustCenter/sectxt#75

Or pinning PGPy to PR:

• Fix armor regex catastrophic backtracking SecurityInnovation/PGPy#467

So the required PGPy will be:

index 9709248..dfd8fcf 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -126,7 +126,7 @@ packaging==23.1
     #   setuptools-scm
 pathlib2==2.3.7.post1
     # via -r requirements.in
-pgpy==0.6.0
+pgpy @ https://github.com/SecurityInnovation/PGPy/archive/09014c72b4557dd1254cf68a32e50f78515f5f32.zip
     # via sectxt
 pluggy==1.2.0
     # via

Then this probe will run without hanging on the malformed PGP armor (------):

$ docker exec -ti internetnl-develop-app-1 python3 manage.py probe --probe=appsecpriv_web_appsecpriv --domain=www.devolksbank.nl

[bwbroersma]

@mxsasha I agree with the 'is this guaranteed to work' question in regards to only patch PGPy in the requirements of internet.nl, and still having a different PGPy version as sub-dependency of sectxt. I could not find it, so it might be quirky behavior indeed. Better wait for the DTC patch, or pin to the sectxt PR (and then as a result also the PGPy PR).