ignore-intermittent.txt: add 2 tests

Author: oech3

.github/workflows/ignore-intermittent.txt

@@ -6,13 +6,15 @@ tests/expand/bounded-memory
 tests/pr/bounded-memory
 tests/tail/inotify-dir-recreate
 tests/tail/overlay-headers
+tests/tail/pid-pipe
 tests/tail/retry
 tests/tail/tail-n0f
 tests/tail/pipe-f
 tests/timeout/timeout
 tests/tail/symlink
 tests/shuf/shuf-reservoir
 tests/sort/sort-stale-thread-mem
+tests/timeout/timeout-group
 tests/tty/tty-eof
 tests/misc/stdbuf
 tests/misc/usage_vs_getopt