CI: don't install libwww-perl

We no longer need the libwww-perl package, as the Makefile now uses curl to
download minisat.

Author: kroening

.github/workflows/pull-request-checks.yaml

@@ -39,7 +39,6 @@ jobs:
         run: ccache -z --max-size=500M
       - name: Get minisat
         run: |
-          sudo apt-get install libwww-perl
           make -C lib/cbmc/src minisat2-download
       - name: Build with make
         run: make -C src -j2 CXX="ccache g++"
@@ -87,7 +86,6 @@ jobs:
         run: ccache -z --max-size=500M
       - name: Get minisat
         run: |
-          sudo apt-get install libwww-perl
           make -C lib/cbmc/src minisat2-download
       - name: Build with make
         run: |