fix: use --keep-cr option for git am

[dsanders11]

If the file being patched has CRLF line endings, git am will fail to apply an otherwise good patch. That's what causes the backport to 24-x-y on electron/electron#37603 to fail.

This change refs script/lib/git.py in e/e where the --keep-cr option is enabled by default with the usage of git am for applying patches there, for this same reason:

# Keep the CR of CRLF in case any patches target files with Windows line
# endings.
args += ['--keep-cr']

For reference, here are the logs for the failed backport on that PR:

backportImpl: Fetching squash commit details
backportImpl: Got squash commit details
backportImpl: Checking out target: "target_repo/24-x-y" to temp: "trop/24-x-y-bp-docs-change-msdn-links-to-new-microsoft-docs-1679680976297"
backportCommitsToBranch: Backporting 1 commits to 24-x-y
backportCommitsToBranch: The provided temporary branch name "trop/24-x-y-bp-docs-change-msdn-links-to-new-microsoft-docs-1679680976297" already exists, deleting existing ref before backporting
backportCommitsToBranch: Failed to apply patch to 24-x-y,Error: Applying: docs: change MSDN links to new Microsoft docs
Using index info to reconstruct a base tree...
M	docs/api/browser-window.md
M	docs/api/native-image.md
Patch failed at 0001 docs: change MSDN links to new Microsoft docs
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".
error: patch failed: docs/fiddles/menus/customize-menus/index.html:70
error: docs/fiddles/menus/customize-menus/index.html: patch does not apply
error: Did you hand edit your patch?
It does not apply to blobs recorded in its index.
hint: Use 'git am --show-current-patch' to see the failed patch
backportImpl: Cherry picking commits to branch failed
Error: Cherry picking commit(s) to branch failed
    at Queue_1.default.enterQueue.annotations (/app/lib/utils.js:344:19)
removeLabel: Removing target/24-x-y from PR #37603

[VerteDinde]

Nice find!