Vita: Install bash in CI.

The wrapper `arm-vita-eabi-pkg-config` fails without it with the error:
`env: can't execute 'bash': No such file or directory`

.github/workflows/vita.yaml

@@ -16,7 +16,7 @@ jobs:
     - name: Install build requirements
       run: |
         apk update 
-        apk add cmake ninja pkgconf
+        apk add cmake ninja pkgconf bash
     - name: Configure CMake
       run: |
         cmake -S . -B build -G Ninja \