Use 26.4 runtimes in macos-latest CI

.github/workflows/unit_tests.yml

@@ -13,27 +13,30 @@ jobs:
   tests:
     runs-on: 'macos-latest'
 
-    timeout-minutes: 15
+    timeout-minutes: 30
 
     env:
       SCHEME: "BlackBoxFirebasePerformance"
-      OS_VERSION: "26.2"
+      OS_VERSION: "26.4"
 
     strategy:
       matrix:
         include:
           - destination: "platform=iOS Simulator"
             platform: ios
+            download_platform: "iOS"
             device: "iPhone 17"
             system_prefix: "iOS"
           - destination: "platform=OS X"
             platform: macos
           - destination: "platform=tvOS Simulator"
             platform: tvos
+            download_platform: "tvOS"
             device: "Apple TV 4K (3rd generation)"
             system_prefix: "tvOS"
           - destination: "platform=watchOS Simulator"
             platform: watchos
+            download_platform: "watchOS"
             device: "Apple Watch Ultra 3 (49mm)"
             system_prefix: "watchOS"
 
@@ -47,14 +50,46 @@ jobs:
       - name: Resolve Dependencies
         run: xcodebuild -resolvePackageDependencies
 
+      - name: Resolve Simulator Runtime
+        if: matrix.platform != 'macos'
+        id: resolve-runtime
+        run: |
+          platform="${{ matrix.system_prefix }}"
+          requested="${{ env.OS_VERSION }}"
+          selected=""
+
+          if xcrun simctl list runtimes | grep -Fq "${platform} ${requested}"; then
+            selected="${requested}"
+          elif xcodebuild -downloadPlatform ${{ matrix.download_platform }} -buildVersion "${requested}" && \
+            xcrun simctl list runtimes | grep -Fq "${platform} ${requested}"; then
+            selected="${requested}"
+          fi
+
+          if [ -z "${selected}" ]; then
+            selected="$(
+              xcrun simctl list runtimes |
+              awk -v platform="${platform}" '$0 ~ "^" platform " 26\\." && $0 !~ /unavailable/ { print $2 }' |
+              sort -V |
+              tail -1
+            )"
+          fi
+
+          if [ -z "${selected}" ]; then
+            echo "No available ${platform} 26.x runtime found" >&2
+            exit 1
+          fi
+
+          echo "Using ${platform} runtime ${selected}"
+          echo "version=${selected}" >> "$GITHUB_OUTPUT"
+
       - name: Create Simulator
         id: create_simulator
         if: matrix.platform != 'macos'
         uses: ./.github/actions/create_sim
         with:
           name: ${{ matrix.device }}
           device: ${{ matrix.device }}
-          system: ${{ matrix.system_prefix }}${{ env.OS_VERSION }}
+          system: ${{ matrix.system_prefix }}${{ steps.resolve-runtime.outputs.version }}
 
       - name: Select Destination
         id: select-destination