Update Doxygen and theme versions

Author: dmadison

.github/workflows/docs.yml

@@ -26,7 +26,7 @@ jobs:
 
       - name: Install Doxygen
         env: 
-          DOXYGEN_VERSION: 1.9.3
+          DOXYGEN_VERSION: 1.9.7
         run: |
           wget -q https://www.doxygen.nl/files/doxygen-${{ env.DOXYGEN_VERSION }}.linux.bin.tar.gz
           tar -xf doxygen-${{ env.DOXYGEN_VERSION }}.linux.bin.tar.gz
@@ -35,7 +35,7 @@ jobs:
 
       - name: Install Themes
         env:
-          DOXYGEN_AWESOME_VERSION: 2.0.3
+          DOXYGEN_AWESOME_VERSION: 2.2.1
         working-directory: ./docs
         run: |
           git clone --depth 1 -b v${{ env.DOXYGEN_AWESOME_VERSION }} https://github.com/jothepro/doxygen-awesome-css