CI: Install Psdyac dependencies

.github/workflows/deploy-book.yml

@@ -1,4 +1,4 @@
-name: Build and Deploy Jupyter Book
+name: Build IGA-Python Jupyter Book
 
 on:
   push:
@@ -20,8 +20,28 @@ jobs:
         cache-dependency-path: |
           requirements.txt
 
+    - name: Install non-Python dependencies on Ubuntu
+      if: matrix.os == 'ubuntu-latest'
+      uses: awalsh128/cache-apt-pkgs-action@latest
+      with:
+        packages: gfortran openmpi-bin libopenmpi-dev libhdf5-openmpi-dev
+        version: 1.0
+        execute_install_scripts: true
+
+    # When loading cached apt packages, the default MPI compiler isn't set.
+    # Workaround is to 'reinstall' openmpi-bin, which doesn't actually perform
+    # installation (since openmpi-bin already exists), but instead reruns
+    # `update-alternatives` which fixes the symlinks to mpicc/mpif90.
+    - name: Set default MPI and HDF5 C compilers on Ubuntu
+      if: matrix.os == 'ubuntu-latest'
+      run: |
+        sudo apt-get update
+        sudo apt-get install --reinstall openmpi-bin libhdf5-openmpi-dev
+
     - name: Install Jupyter Book and Psydac
-      run: pip3 install -r requirements.txt
+      run: |
+        pip3 install --upgrade pip
+        pip3 install -r requirements.txt
 
     - name: Build Jupyter Book
       run: jupyter-book build .