ci/freedreno: Switch the piglit job to using a deqp-runner suite.

This is one of the few remaining piglit-runner.sh users.

I think the notable change here is that we no longer set
EGL_PLATFORM=surfaceless like the piglit-runner.sh script did.

Acked-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Acked-by: Karol Herbst <kherbst@redhat.com>
Acked-by: Martin Roukala <martin.roukala@mupuf.org>
Acked-by: David Heidelberg <david.heidelberg@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20798>

src/freedreno/ci/deqp-freedreno-a630-piglit.toml

@@ -0,0 +1,6 @@
+[[piglit]]
+piglit_folder = "/piglit"
+profile = "gpu"
+process_isolation = true
+  [piglit.env]
+  PIGLIT_NO_WINDOW = "1"

src/freedreno/ci/gitlab-ci.yml

@@ -306,13 +306,13 @@ a630_vk_asan:
 
 a630_piglit:
   extends:
-    - .piglit-test
+    - .baremetal-deqp-test
     - .a630-test
     # Note that piglit has GL+VK integration testing.
     - .freedreno-turnip-rules
   variables:
     HWCI_START_XORG: 1
-    PIGLIT_PROFILES: gpu
+    DEQP_SUITE: freedreno-a630-piglit
 
 a630-traces:
   extends: