ci: do not mount already mounted directories

In some cases we are using an initramfs image that pre-mounts some of
the directories, so let's skip them in the next stage.

Reviewed-by: Eric Engestrom <eric@igalia.com>
Reviewed-by: David Heidelberg <david.heidelberg@collabora.com>
Signed-off-by: Juan A. Suarez Romero <jasuarez@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/26552>
(cherry picked from commit d0ae58f413)

.gitlab-ci/common/init-stage1.sh

@@ -7,10 +7,10 @@ set -ex
 
 cd /
 
-mount -t proc none /proc
-mount -t sysfs none /sys
+findmnt --mountpoint /proc || mount -t proc none /proc
+findmnt --mountpoint /sys || mount -t sysfs none /sys
 mount -t debugfs none /sys/kernel/debug
-mount -t devtmpfs none /dev || echo possibly already mounted
+findmnt --mountpoint /dev || mount -t devtmpfs none /dev
 mkdir -p /dev/pts
 mount -t devpts devpts /dev/pts
 mkdir /dev/shm

.pick_status.json

@@ -4234,7 +4234,7 @@
         "description": "ci: do not mount already mounted directories",
         "nominated": false,
         "nomination_type": 3,
-        "resolution": 4,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": null,
         "notes": null