ci: report the typecheck job green (step-level continue-on-error)

Job-level continue-on-error still surfaces the job as a failed check on the
PR; moving it to the mypy step lets the job pass green while mypy stays
advisory.

Author: jm

.github/workflows/tests.yml

@@ -56,13 +56,14 @@ jobs:
 
   typecheck:
     runs-on: ubuntu-latest
-    # Non-blocking: strict typing is being introduced incrementally.
-    continue-on-error: true
     steps:
       - uses: actions/checkout@v6
 
       - name: Install uv
         uses: astral-sh/setup-uv@v6
 
       - name: Mypy
+        # Non-blocking: strict typing is being introduced incrementally, so a
+        # mypy failure is reported but does not fail the (green) job.
+        continue-on-error: true
         run: uvx --with requests --with pysolr mypy dspace_rest_client