Disable core.protectNTFS (#17300)

Disable core.protectNTFS (#17300)

core.protectNTFS protects NTFS from files which may be difficult to remove or interact
with using the win32 api, however, it also appears to prevent such files from
being entered into the git indexes - fundamentally causing breakages with PRs that
affect these files. However, deliberately setting this to false may cause security
issues due to the remain sparse checkout of files in the merge pipeline.

The only sensible option therefore is to provide an optional setting which admins
could set which would forcibly switch this off if they are affected by this issue.

Fix #17092

Signed-off-by: Andrew Thornton <art27@cantab.net>