Android Editor builds fail due to storage problems

[NuclearCookie]

Bug description

As you can see in the GitHub Actions, the last few 6.3.X builds failed to complete.
https://github.com/game-ci/docker/actions/runs/21362813556

It looks like the root cause is that the build process runs out of diskspace during a caching process.

Additional details

I am not very familiar with this workflow and I did ask ChatGPT for help, so I am not sure if this is a good suggestion. That's why I didn't make a PR but an issue instead.
AI suggests to offload buildx caching from tmp/ to mnt/ which might gives us more diskspace.

diff --git a/.github/workflows/new-ubuntu-post-2019-2-editor-image-requested.yml b/.github/workflows/new-ubuntu-post-2019-2-editor-image-requested.yml
index 1234567..abcdef0 100644
--- a/.github/workflows/new-ubuntu-post-2019-2-editor-image-requested.yml
+++ b/.github/workflows/new-ubuntu-post-2019-2-editor-image-requested.yml
@@ -95,6 +95,13 @@ jobs:
       - name: Free disk space
         run: .github/workflows/scripts/free_disk_space.sh

+      ############################
+      #   Prepare buildx cache   #
+      ############################
+      - name: Prepare buildx cache dir
+        run: |
+          sudo mkdir -p /mnt/buildx-cache
+          sudo chown -R $USER:$USER /mnt/buildx-cache
+
       ############################
       #   Pull previous images   #
       ############################
@@ -118,8 +125,8 @@ jobs:
             changeSet=${{ github.event.client_payload.changeSet }}
             module=${{ matrix.targetPlatform }}
-          cache-from: type=local,src=/tmp/.buildx-cache
-          cache-to: type=local,dest=/tmp/.buildx-cache
+          cache-from: type=local,src=/mnt/buildx-cache
+          cache-to: type=local,dest=/mnt/buildx-cache
           push: true
           tags: |
             unityci/editor:${{ github.event.client_payload.editorVersion }}-${{ matrix.targetPlatform }}-${{ github.event.client_payload.repoVersionFull }}
@@ -152,8 +159,8 @@ jobs:
             changeSet=${{ github.event.client_payload.changeSet }}
             module=${{ matrix.targetPlatform }}
-          cache-from: type=local,src=/tmp/.buildx-cache
-          cache-to: type=local,dest=/tmp/.buildx-cache
+          cache-from: type=local,src=/mnt/buildx-cache
+          cache-to: type=local,dest=/mnt/buildx-cache
           push: true
           tags: |
             unityci/editor:${{ github.event.client_payload.editorVersion }}-${{ matrix.targetPlatform }}-${{ github.event.client_payload.repoVersionFull }}