testsuite.yml: fix ASAN build tests

This works around actions/runner-images#9491

Apparently a recent Ubuntu update changed the ASLR entropy to
use more bits which is incompatible with ASAN as shipped with
Ubuntu.

This adjusts the entropy bits to be compatible with ASAN.

Thanks to ilmari who found the ticket linked above.

.github/workflows/testsuite.yml

@@ -720,6 +720,9 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y libgdbm-dev libdb-dev
       - uses: actions/checkout@v3
+      # this can be removed once https://github.com/actions/runner-images/issues/9491 is fixed
+      - name: Reduce ASLR entropy
+        run: sudo sysctl -w vm.mmap_rnd_bits=28
       - name: git cfg
         run: |
           git config diff.renameLimit 999999
@@ -768,6 +771,9 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y libgdbm-dev libdb-dev
       - uses: actions/checkout@v3
+      # this can be removed once https://github.com/actions/runner-images/issues/9491 is fixed
+      - name: Reduce ASLR entropy
+        run: sudo sysctl -w vm.mmap_rnd_bits=28
       - name: git cfg
         run: |
           git config diff.renameLimit 999999