ci/lava: Use init-stage2 and setup-test-env.sh from Mesa install

init-stage2.sh and setup-test-env.sh are already downloaded on the DUT as
part of the mesa-build overlay, which downloads the Mesa artifacts from
S3.

Signed-off-by: Valentine Burley <valentine.burley@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35051>

.gitlab-ci/tests/data/FASTBOOT_force_uart=False_job_definition.yaml

@@ -138,6 +138,6 @@ actions:
             sed -i '/S3_RESULTS_UPLOAD/d' /set-job-env-vars.sh
             EOF
           - export SSH_PTY_ARGS=-tt
-          - lava_ssh_test_case 'test-project_dut' 'cd / && /init-stage2.sh'
+          - lava_ssh_test_case 'test-project_dut' 'cd / && /test_dir/install/common/init-stage2.sh'
     docker:
       image:

.gitlab-ci/tests/data/FASTBOOT_force_uart=True_job_definition.yaml

@@ -90,4 +90,4 @@ actions:
           - echo Could not find jwt file, disabling S3 requests...
           - sed -i '/S3_RESULTS_UPLOAD/d' /set-job-env-vars.sh
           - sleep 1
-          - lava-test-case 'test-project_dut' --shell /init-stage2.sh
+          - lava-test-case 'test-project_dut' --shell /test_dir/install/common/init-stage2.sh

.gitlab-ci/tests/data/UBOOT_force_uart=False_job_definition.yaml

@@ -109,6 +109,6 @@ actions:
             sed -i '/S3_RESULTS_UPLOAD/d' /set-job-env-vars.sh
             EOF
           - export SSH_PTY_ARGS=-tt
-          - lava_ssh_test_case 'test-project_dut' 'cd / && /init-stage2.sh'
+          - lava_ssh_test_case 'test-project_dut' 'cd / && /test_dir/install/common/init-stage2.sh'
     docker:
       image:

.gitlab-ci/tests/data/UBOOT_force_uart=True_job_definition.yaml

@@ -63,4 +63,4 @@ actions:
           - echo Could not find jwt file, disabling S3 requests...
           - sed -i '/S3_RESULTS_UPLOAD/d' /set-job-env-vars.sh
           - sleep 1
-          - lava-test-case 'test-project_dut' --shell /init-stage2.sh
+          - lava-test-case 'test-project_dut' --shell /test_dir/install/common/init-stage2.sh