Revert "Bump pynacl from 1.5.0 to 1.6.2 in /utils/git" (#8050)

Reverts #8045

Looks like this is actually breaking the formatting checks - so we have to bypass the rules to merge this!

Author: damyanp

utils/git/requirements_formatting.txt

@@ -40,7 +40,7 @@ pygithub==1.59.1
     # via -r llvm/utils/git/requirements_formatting.txt.in
 pyjwt[crypto]==2.8.0
     # via pygithub
-pynacl==1.6.2
+pynacl==1.5.0
     # via pygithub
 requests==2.32.4
     # via pygithub