tests: actually test the non-mmap case in `test-branches.t`
It looks like
40943970b7ae renamed the config, but also flipped it to 'on' by
default, and the test file didn't keep up. I noticed because all 4 test cases
failed on Windows due to a mmap problem, and there only should have been 2.
--- a/tests/test-branches.t Thu Oct 17 15:34:45 2024 -0400
+++ b/tests/test-branches.t Fri Oct 18 13:45:13 2024 -0400
@@ -6,6 +6,11 @@
> [storage]
> revbranchcache.mmap=true
> EOF
+#else
+ $ cat <<EOF >> $HGRCPATH
+ > [storage]
+ > revbranchcache.mmap=false
+ > EOF
#endif
#if v3