[Build] Fixes (#1382)

The Docs build was running out of disk space, so move to `Large_Linux` nodes (not sure what caused this, but it's not a high priority to run down).

Also fix a small issue in the Notebooks build. Since there are now two `pytest` invocations, we need to make sure that the second doesn't overwrite coverage results from the first.

Author: riedgar-ms

.github/workflows/ci_docs.yml

@@ -22,7 +22,7 @@ on:
 
 jobs:
   check_ReadMe:
-    runs-on: ubuntu-latest
+    runs-on: Large_Linux
     environment: test
     strategy:
       fail-fast: false # Don't cancel all on first failure

.github/workflows/notebook_tests.yml

@@ -76,7 +76,7 @@ jobs:
             ./tests/notebooks/test_notebooks_azure.py
 
           # Then do the rest
-          pytest -vv --cov=guidance --cov-report=xml --cov-report=term-missing \
+          pytest -vv --cov=guidance --cov-report=xml --cov-report=term-missing --cov-append \
             ./tests/notebooks/test_notebooks.py
       - name: Upload coverage reports to Codecov
         uses: codecov/codecov-action@v5