t/perf: avoid copying builtin fsmonitor files into test repo

Do not try to copy a fsmonitor--daemon socket from the current
development directory into the test trash directory.

When we run the perf suite without an explicit source repo set,
we copy of the current $GIT_DIR into the test trash directory.
Unix domain sockets cannot be copied in that manner, so the test
setup fails.

Additionally, omit any other fsmonitor--daemon temp files inside
the $GIT_DIR directory.

Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>

t/perf/perf-lib.sh

@@ -74,7 +74,7 @@ test_perf_copy_repo_contents () {
 	for stuff in "$1"/*
 	do
 		case "$stuff" in
-		*/objects|*/hooks|*/config|*/commondir|*/gitdir|*/worktrees)
+		*/objects|*/hooks|*/config|*/commondir|*/gitdir|*/worktrees|*/fsmonitor--daemon*)
 			;;
 		*)
 			cp -R "$stuff" "$repo/.git/" || exit 1