ci: Don't run Meson tests in critical-path jobs

Running the Meson tests doesn't take forever, but it does take a
noticeable amount of time.

For jobs in the critical path - like debian-testing and debian-arm64 -
we need them to complete as soon as possible to produce a build for the
hardware tests to consume. Running the tests here lengthens that time,
and introduces more hazard since the tests have previously been prone to
hitting timeouts, requiring the whole job to be retried before we can
proceed. These jobs also have build-only jobs which are not in the
critical path, and can run the tests just as well.

Running the tests under sanitisers is just too slow to deal with in
pre-merge pipelines.

Signed-off-by: Daniel Stone <daniels@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33137>

.gitlab-ci/meson/build.sh

@@ -158,7 +158,7 @@ meson setup _build \
       -D prefix=$PWD/install \
       -D libdir=lib \
       -D buildtype=${BUILDTYPE:?} \
-      -D build-tests=true \
+      -D build-tests=${RUN_MESON_TESTS} \
       -D c_args="$(echo -n $C_ARGS)" \
       -D c_link_args="$(echo -n $C_LINK_ARGS)" \
       -D cpp_args="$(echo -n $CPP_ARGS)" \
@@ -182,9 +182,11 @@ uncollapsed_section_switch meson-build "meson: build"
 
 ninja
 
+if [ "${RUN_MESON_TESTS}" = "true" ]; then
+    uncollapsed_section_switch meson-test "meson: test"
+    LC_ALL=C.UTF-8 meson test --num-processes "${FDO_CI_CONCURRENT:-4}" --print-errorlogs ${MESON_TEST_ARGS}
+fi
 
-uncollapsed_section_switch meson-test "meson: test"
-LC_ALL=C.UTF-8 meson test --num-processes "${FDO_CI_CONCURRENT:-4}" --print-errorlogs ${MESON_TEST_ARGS}
 section_switch meson-install "meson: install"
 ninja install
 cd ..