fix(ci): use bash in playwright container

Author: jfix

.github/workflows/daily-new-mosaics.yml

@@ -28,6 +28,9 @@ jobs:
         timeout-minutes: 120
         container:
             image: "mcr.microsoft.com/playwright:v1.58.2-noble"
+        defaults:
+            run:
+                shell: bash
 
         env:
             SI_REFERENCE_LIBRARY: ${{ github.workspace }}