tests: Update the Weekly tests' docker version to v22-0

Change-Id: I9940c78396fffb5a009f86a968bc847f6285312d
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/60550
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
1 file changed