Redo the testwrapper to track and only retry flaky tests instead
of retrying the entire pkg. It also fails early if a non-flaky test fails.
This also makes it so that the go test caches are used.
Fixes#7975
Signed-off-by: Maisem Ali <maisem@tailscale.com>
This updates all source files to use a new standard header for copyright
and license declaration. Notably, copyright no longer includes a date,
and we now use the standard SPDX-License-Identifier header.
This commit was done almost entirely mechanically with perl, and then
some minimal manual fixes.
Updates #6865
Signed-off-by: Will Norris <will@tailscale.com>
