update template to default to Typst 0.12

Author: SillyFreak

.github/workflows/tests.yml

@@ -10,11 +10,11 @@ jobs:
     strategy:
       matrix:
         # add any other Typst versions that your package should support
-        typst-version: ["0.11"]
+        typst-version: ["0.12"]
         # the docs don't need to build with all versions supported by the package;
         # the latest one is enough
         include:
-          - typst-version: "0.11"
+          - typst-version: "0.12"
             doc: 1
     runs-on: ubuntu-latest
     steps: