[skip ci] Fix --enable-dl-test flag being passed to PHP-8.0 MSAN build

.github/workflows/nightly.yml

@@ -427,11 +427,11 @@ jobs:
             --enable-calendar \
             --enable-ftp \
             --enable-zend-test \
-            --enable-dl-test=shared \
             --enable-werror \
             --enable-memory-sanitizer \
             --with-config-file-path=/etc \
-            --with-config-file-scan-dir=/etc/php.d
+            --with-config-file-scan-dir=/etc/php.d \
+            ${{ matrix.branch.ref != 'PHP-8.0' && '--enable-dl-test=shared' }}
       - name: make
         run: make -j$(/usr/bin/nproc) >/dev/null
       - name: make install