Update book.yml

Author: pnavaro

.github/workflows/book.yml

@@ -13,10 +13,9 @@ jobs:
     - uses: fortran-lang/setup-fortran@v1
       with:
           compiler: gcc
-          - name: Install fortran
-    - name: Install LaPack
+    - name: Install LaPack and FFTW
       run:
-        sudo apt-get install libblas-dev liblapack-dev
+        sudo apt-get install libblas-dev liblapack-dev libfftw3-dev
       shell: bash
     - uses: actions/setup-python@v5
       with: