I notice all other file reads in checksrc are handled with $windows_os ? $_ =~ s/\r?\n$// : chomp; so I propose we do that instead:

diff --git a/scripts/checksrc.pl b/scripts/checksrc.pl
index 76f4660..be085e0 100755
--- a/scripts/checksrc.pl
+++ b/scripts/checksrc.pl
@@ -120,6 +120,7 @@ sub readlocalfile {
     open(my $rcfile, "<", "$dir/.checksrc") or return;
 
     while(<$rcfile>) {
+        $windows_os ? $_ =~ s/\r?\n$// : chomp;
         $i++;
 
         # Lines starting with '#' are considered comments

We can use both fixes.
There is no reason to have LF->CRLF transformation in .checksrc files.

Thanks. I landed this but omitted the gitattributes change. IMO there's no reason to have a special exception since it can now be handled like the other input files.