Windows shell quoting: *shakes fist again*

Author: japhb

.github/workflows/test.yml

@@ -31,6 +31,6 @@ jobs:
       - name: Install Dependencies
         run: zef install --/test --test-depends --deps-only .
       - name: Install App::Prove6
-        run: zef install --/test 'App::Prove6:ver<0.0.15>'
+        run: zef install --/test "App::Prove6:ver<0.0.15>"
       - name: Run Tests
         run: prove6 -l -v t