Rewrite Entitlements.plist to avoid newline issues.

[alcarithemad]

The macOS utility codesign fails with obscure, difficult to debug errors when presented with CRLF newlines in an XML format Entitlements.plist.

Git can be configured globally to mangle newlines to CRLF (via core.autocrlf=true).

Cookiecutter manages the git clone of the template, so there's no easy way for us to set the configuration at the repository level during the template instantiation process.

To prevent a build failure that bit someone during the PyCon US 2024 sprints, the post_gen_projecct hook now reads the Entitlements.plist file and writes it back with the LF newlines that codesign expects.

I tested this by generating a new project locally after running git config --global core.autocrlf true and verifying that the build fails during signing (and confirmed that the templated file has CRLF newlines). Then, I configured the project to use this branch and successfully built and signed the template app, despite still having the Git option enabled.

Fixes beeware/briefcase#1831

PR Checklist:

• All new features have been tested
• All new features have been documented
• I have read the CONTRIBUTING.md file
• I will abide by the code of conduct

[freakboy3742]

Looks good; it might be worth doing the same thing to the Info.plist file. There's no evidence that this is actually causing problems, but given it's also a plist and some tooling has a problem, it would be worth fixing pre-emptively.

[alcarithemad]

Added Info.plist rewrite.

[freakboy3742]

Awesome - thanks for the fix!