CI: revert kernel addr randomization introduced in 3a0fc864

It has been resolved on image generation side:
https://github.com/actions/runner-images/issues/9491

It is no harm to keep it on our side as well, but we can drop it.

.github/workflows/vtest.yml

@@ -64,17 +64,6 @@ jobs:
       run: |
         echo "key=$(echo ${{ matrix.name }} | sha256sum | awk '{print $1}')" >> $GITHUB_OUTPUT
 
-
-#
-# temporary hack
-# should be revisited after https://github.com/actions/runner-images/issues/9491 is resolved
-#
-
-    - name: Setup enthropy
-      if: ${{ startsWith(matrix.os, 'ubuntu-') }}
-      run: |
-        sudo sysctl vm.mmap_rnd_bits=28
-
     - name: Cache SSL libs
       if: ${{ matrix.ssl && matrix.ssl != 'stock' && matrix.ssl != 'BORINGSSL=yes' && matrix.ssl != 'QUICTLS=yes' }}
       id: cache_ssl