ci: refactor workflows to use reusable workflow calls

Updated build workflows to use workflow_call triggers and accept ci_version as input, removing inline CI version generation. Upgraded all actions to v5 and added a new build.yml workflow to orchestrate builds for AppImage, Steam Link, and Windows/macOS using reusable workflows. This improves maintainability and consistency across CI jobs.

.github/workflows/build-win-mac.yml

@@ -1,12 +1,19 @@
-name: Build Windows and macOS
+---
+name: Build - Windows and macOS
+permissions:
+  contents: read
 
 on:
-  push:
-  pull_request:
-    branches: [ "master" ]
+  workflow_call:
+    inputs:
+      ci_version:
+        required: true
+        type: string
 
 jobs:
   build:
+    env:
+      CI_VERSION: ${{ inputs.ci_version }}
     strategy:
       fail-fast: false
       matrix:
@@ -22,17 +29,11 @@ jobs:
 
     steps:
       - name: Checkout Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@v5
         with:
           submodules: 'recursive'
           fetch-depth: 1
 
-      - name: Set CI version
-        shell: bash
-        run: |
-          CI_VERSION=`echo $GITHUB_SHA | cut -c1-6`
-          echo "CI_VERSION=$CI_VERSION" >> $GITHUB_ENV
-
       - name: Install create-dmg (macOS)
         if: runner.os == 'macOS'
         run: |
@@ -85,7 +86,7 @@ jobs:
           }
 
       - name: Upload Binaries (Windows x64)
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v5
         if: runner.os == 'Windows'
         with:
           name: Moonlight-${{ runner.os }}-x64-${{ env.CI_VERSION }}
@@ -93,7 +94,7 @@ jobs:
           if-no-files-found: error
 
       - name: Upload Binaries (Windows arm64)
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v5
         if: runner.os == 'Windows'
         with:
           name: Moonlight-${{ runner.os }}-arm64-${{ env.CI_VERSION }}
@@ -101,7 +102,7 @@ jobs:
           if-no-files-found: error
 
       - name: Upload Binaries (macOS)
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v5
         if: runner.os == 'macOS'
         with:
           name: Moonlight-${{ runner.os }}-${{ env.CI_VERSION }}
@@ -110,7 +111,7 @@ jobs:
           if-no-files-found: error
 
       - name: Upload Symbols
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v5
         with:
           name: zDevDbgSyms-${{ runner.os }}-${{ env.CI_VERSION }}
           path: |