Added sccache to CI runs.

.github/workflows/build-app.yaml

@@ -1,12 +1,25 @@
 name: build-app
-on: [push]
-
+on:
+  push:
+  workflow_call:
+    inputs:
+      disable_sccache:
+        required: false
+        type: boolean
 jobs:
   build:
     runs-on: macos-13
     steps:
+      - name: Run sccache-cache unless disabled
+        if: inputs.disable_sccache != true
+        uses: mozilla-actions/[email protected]
       - name: Select Xcode 15
         run: sudo xcode-select -s '/Applications/Xcode_15.0.1.app/Contents/Developer'
+      - name: Set Rust caching env vars only on non-release runs
+        if: inputs.disable_sccache != true
+        run: |
+          echo "SCCACHE_GHA_ENABLED=true" >> $GITHUB_ENV
+          echo "TES3MP_MAC_USE_SCCACHE=1" >> $GITHUB_ENV
       - uses: actions/checkout@v4
       - run: brew install coreutils create-dmg gnu-sed meson nasm ninja patchutils python-setuptools
       - name: Build