Conda install gmt dev version directly in one step instead of two (#1279)

See if the dependency resolver works better if we install
GMT dev and NumPy et al. directly in one `conda install`
step, instead of having a two step process.

Author: weiji14

.github/workflows/ci_docs.yml

@@ -66,8 +66,8 @@ jobs:
       # Install GMT and other required dependencies from conda-forge
       - name: Install dependencies
         run: |
-          conda install -c conda-forge/label/dev gmt=6.2.0rc1
-          conda install numpy pandas xarray netCDF4 packaging \
+          conda install conda-forge/label/dev::gmt=6.2.0rc1 \
+                        numpy pandas xarray netCDF4 packaging \
                         ipython make myst-parser \
                         sphinx sphinx-copybutton sphinx-gallery sphinx_rtd_theme
 

.github/workflows/ci_tests.yaml

@@ -89,8 +89,8 @@ jobs:
       # Install GMT and other required dependencies from conda-forge
       - name: Install dependencies
         run: |
-          conda install -c conda-forge/label/dev gmt=6.2.0rc1
-          conda install numpy=${{ matrix.numpy-version }} \
+          conda install conda-forge/label/dev::gmt=6.2.0rc1 \
+                        numpy=${{ matrix.numpy-version }} \
                         pandas xarray netCDF4 packaging \
                         ${{ matrix.optional-packages }} \
                         codecov coverage[toml] dvc ipython make \