ci: configure tests-on-pr.yml to run without environment.yml

Author: cadenmyers13

.github/workflows/tests-on-pr.yml

@@ -28,22 +28,25 @@ jobs:
       - name: Initialize miniconda
         uses: conda-incubator/setup-miniconda@v3
         with:
-          activate-environment: test
           auto-update-conda: true
-          environment-file: environment.yml
           auto-activate-base: false
           python-version: ${{ matrix.python-version }}
-
       - name: Conda config
-        run: >-
-          conda config --set always_yes yes
-          --set changeps1 no
-
+        run: |
+          conda config --add channels conda-forge
       - name: Install diffpy.srreal and requirements
         run: |
-          conda install --file requirements/conda.txt
-          conda install --file requirements/test.txt
+          conda create -n test python=${{ matrix.python-version }} -y
+          source $(conda info --base)/etc/profile.d/conda.sh
+          conda activate test
+          conda install pip -y
+          conda config --set always_yes yes --set changeps1 no
+          conda install --file requirements/conda.txt -y
+          conda install --file requirements/test.txt -y
           python -m pip install . --no-deps
 
       - name: Validate diffpy.pdfgui
-        run: pytest tests
+        run: |
+          source $(conda info --base)/etc/profile.d/conda.sh
+          conda activate test
+          pytest tests