Merge pull request matplotlib#24920 from ksunden/nightly_only_bin

Add --only-binary to nightly pip install

Author: oscargus

.github/workflows/tests.yml

@@ -227,7 +227,7 @@ jobs:
         # Only install the nightly dependencies during the scheduled event
         if: ${{ github.event_name == 'schedule' && matrix.name-suffix != '(Minimum Versions)' }}
         run: |
-          python -m pip install -i https://pypi.anaconda.org/scipy-wheels-nightly/simple --upgrade numpy pandas
+          python -m pip install -i https://pypi.anaconda.org/scipy-wheels-nightly/simple --upgrade --only-binary=:all: numpy pandas
 
       - name: Install Matplotlib
         run: |