Use single quotes for literal cache keys

Swapping to single quotes avoids YAML escaping surprises.

Author: networkfusion

azure-pipelines-templates/download-install-arm-gcc-toolchain.yml

@@ -11,7 +11,7 @@ steps:
     condition: eq(variables.GccArm_Version, '')
     displayName: Cache latest ARM GCC toolchain
     inputs:
-      key: "gcc-14_2__rel1 | gccUpdateKey"
+      key: 'gcc-14_2__rel1 | gccUpdateKey'
       restoreKeys: gccUpdateKey
       path: $(Agent.TempDirectory)\arm-gnu-toolchain-${{ parameters.gccArmVersion }}-mingw-w64-i686-arm-none-eabi
       cacheHitVar: GCC_CACHE_RESTORED