t6137-pathspec-wildcards-literal.sh is failing at v2.51.0. git bisect points to the failure existing since the test script was introduced in gitster/git@ec727e1.
My guess is this is related to the Cygwin libraries doing some glob expansion in addition to the shell, in the name of improving compatibility when calling a Cygwin executable (which will have expected the shell to do any glob expansion) from the Windows command line (which expects executables to do their own glob expansion).
This is another FUNNYNAMES test.