Merge branch 'kk/wildmatch-windows-ls-files-prereq'

In t3070-wildmatch, "via ls-files" test variants with patterns
containing backslash escapes are now skipped on Windows, avoiding 36
test failures caused by pathspec separator conversion.

* kk/wildmatch-windows-ls-files-prereq:
  t3070: skip ls-files tests with backslash patterns on Windows