Avery found a bunch of tests that fail with -count=2.
Updates tailscale/corp#40176 (tracks making our CI detect them)
Change-Id: Ie3e4398070dd92e4fe0146badddf1254749cca20
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Co-authored-by: Avery Pennarun <apenwarr@tailscale.com>