CI: Disable Panfrost T7x0 jobs

One of the dispatchers in the office (with all the T7x0 boards) has gone
AWOL, and we don't have physical access to restore it. Disable it until
we can get in and fix it.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4965>

.gitlab-ci/lava-gitlab-ci.yml

@@ -76,7 +76,7 @@
     - arm_build
     - meson-arm64
 
-panfrost-t720-gles2:arm64:
+.panfrost-t720-gles2:arm64:
   extends:
     - .lava-test:arm64
     - .panfrost-rules
@@ -89,7 +89,7 @@ panfrost-t720-gles2:arm64:
   tags:
     - mesa-ci-aarch64-lava-collabora
 
-panfrost-t760-gles2:armhf:
+.panfrost-t760-gles2:armhf:
   extends:
     - .lava-test:armhf
     - .panfrost-rules