Cache public assets in CI

If cached assets exist, they will be downloaded which should be quicker than building them again.
Then assets:precompile will build any missing assets, skipping over cached ones.
Then finally, all assets are saved to a newer version of the cache.

It sounds like GitHub automatically manages cache versions based on branch and time, so new branches will inherit the master cache, rather than cache from another branch.

If this works, this generic code should live in a shared module or something.

.github/workflows/build.yml

@@ -67,6 +67,15 @@ jobs:
         run: |
           bin/rake db:create db:schema:load
 
+      - name: Restore cached public assets
+        id: cache-public-restore
+        uses: actions/cache/restore@v4
+        with:
+          path: |
+            public/assets
+            public/packs-test
+          key: public
+
       - name: Run tests
         env:
           KNAPSACK_PRO_TEST_SUITE_TOKEN_RSPEC: 864ef557d85ea8e603e086c0387d5154
@@ -85,6 +94,15 @@ jobs:
           git show --no-patch # the commit being tested (which is often a merge due to actions/checkout@v3)
           bin/rake knapsack_pro:rspec
 
+      - name: Save cached public assets
+        id: cache-public-save
+        uses: actions/cache/save@v4
+        with:
+          path: |
+            public/assets
+            public/packs-test
+          key: public
+
   models:
     runs-on: ubuntu-22.04
     services:
@@ -127,6 +145,15 @@ jobs:
         run: |
           bin/rake db:create db:schema:load
 
+      - name: Restore cached public assets
+        id: cache-public-restore
+        uses: actions/cache/restore@v4
+        with:
+          path: |
+            public/assets
+            public/packs-test
+          key: public
+
       - name: Run tests
         env:
           KNAPSACK_PRO_TEST_SUITE_TOKEN_RSPEC: 09476e2ce491c12083df62768667c674
@@ -144,6 +171,15 @@ jobs:
         run: |
           bin/rake knapsack_pro:rspec
 
+      - name: Save cached public assets
+        id: cache-public-save
+        uses: actions/cache/save@v4
+        with:
+          path: |
+            public/assets
+            public/packs-test
+          key: public
+
   system_admin:
     runs-on: ubuntu-22.04
     services:
@@ -193,8 +229,16 @@ jobs:
         run: |
           bin/rake db:create db:schema:load
 
-      - name: Run tests
+      - name: Restore cached public assets
+        id: cache-public-restore
+        uses: actions/cache/restore@v4
+        with:
+          path: |
+            public/assets
+            public/packs-test
+          key: public
 
+      - name: Run tests
         env:
           KNAPSACK_PRO_TEST_SUITE_TOKEN_RSPEC: ff2456e64c9f2aa5157eb0daf711d3c3
           KNAPSACK_PRO_CI_NODE_TOTAL: ${{ matrix.ci_node_total }}
@@ -212,6 +256,15 @@ jobs:
         run: |
           bin/rake knapsack_pro:queue:rspec
 
+      - name: Save cached public assets
+        id: cache-public-save
+        uses: actions/cache/save@v4
+        with:
+          path: |
+            public/assets
+            public/packs-test
+          key: public
+
       - name: Archive failed tests screenshots
         if: failure()
         uses: actions/upload-artifact@v3
@@ -270,6 +323,15 @@ jobs:
         run: |
           bin/rake db:create db:schema:load
 
+      - name: Restore cached public assets
+        id: cache-public-restore
+        uses: actions/cache/restore@v4
+        with:
+          path: |
+            public/assets
+            public/packs-test
+          key: public
+
       - name: Run tests
 
         env:
@@ -348,8 +410,16 @@ jobs:
         run: |
           bin/rake db:create db:schema:load
 
-      - name: Run tests
+      - name: Restore cached public assets
+        id: cache-public-restore
+        uses: actions/cache/restore@v4
+        with:
+          path: |
+            public/assets
+            public/packs-test
+          key: public
 
+      - name: Run tests
         env:
           KNAPSACK_PRO_TEST_SUITE_TOKEN_RSPEC: d6ea7ceb766404ccd016c19aa2c81b1c
           KNAPSACK_PRO_CI_NODE_TOTAL: ${{ matrix.ci_node_total }}
@@ -367,6 +437,15 @@ jobs:
         run: |
           bin/rake knapsack_pro:rspec
 
+      - name: Save cached public assets
+        id: cache-public-save
+        uses: actions/cache/save@v4
+        with:
+          path: |
+            public/assets
+            public/packs-test
+          key: public
+
       - name: Archive failed tests screenshots
         if: failure()
         uses: actions/upload-artifact@v3
@@ -426,6 +505,15 @@ jobs:
         run: |
           bin/rake db:create db:schema:load
 
+      - name: Restore cached public assets
+        id: cache-public-restore
+        uses: actions/cache/restore@v4
+        with:
+          path: |
+            public/assets
+            public/packs-test
+          key: public
+
       - name: Run tests
         env:
           KNAPSACK_PRO_TEST_SUITE_TOKEN_RSPEC: e3b8800198d2d89b70c7edbdd85f8fd8
@@ -443,6 +531,15 @@ jobs:
         run: |
           bin/rake knapsack_pro:rspec
 
+      - name: Save cached public assets
+        id: cache-public-save
+        uses: actions/cache/save@v4
+        with:
+          path: |
+            public/assets
+            public/packs-test
+          key: public
+
   non_knapsack_jest_karma:
     runs-on: ubuntu-22.04
     services: