Files under tempfork are vendored copies of upstream code that we
want to keep as close to upstream as possible, so don't require them
to use httpm constants. An upcoming tempfork/acme sync brings in
upstream test files using net/http's method constants.
Updates tailscale/corp#45167
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Change-Id: If2a90b1d7c5e8f3a6b4d0c9e2a7f5b8d1c4e6a3f