decode json on matrix paths

Author: David Cavazos

.github/workflows/custard-run-dev.yaml

@@ -61,7 +61,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        path: ${{ needs.affected.outputs.paths }}
+        path: ${{ fromJson(needs.affected.outputs.paths) }}
     continue-on-error: true
     env:
       GOOGLE_SAMPLES_PROJECT: long-door-651

.github/workflows/custard-run.yaml

@@ -100,7 +100,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        path: ${{ needs.affected.outputs.paths }}
+        path: ${{ fromJson(needs.affected.outputs.paths) }}
     continue-on-error: true
     env:
       GOOGLE_SAMPLES_PROJECT: long-door-651