[NFC] Comment on the luarocks installs in the dockerfiles that it is needed for oss-fuzz (#5098)

Author: jonathanmetzman

docker/oss-fuzz/base/Dockerfile

@@ -13,6 +13,7 @@
 # limitations under the License.
 FROM gcr.io/clusterfuzz-images/base
 
+# luarocks is needed for running lua projects in oss-fuzz.
 RUN apt-get update && apt-get install -y luarocks
 
 ENV UPDATE_WEB_TESTS False

docker/oss-fuzz/base/ubuntu-20-04.Dockerfile

@@ -13,6 +13,7 @@
 # limitations under the License.
 FROM gcr.io/clusterfuzz-images/base:ubuntu-20-04
 
+# luarocks is needed for running lua projects in oss-fuzz.
 RUN apt-get update && apt-get install -y luarocks
 
 ENV UPDATE_WEB_TESTS False

docker/oss-fuzz/base/ubuntu-24-04.Dockerfile

@@ -13,6 +13,7 @@
 # limitations under the License.
 FROM gcr.io/clusterfuzz-images/base:ubuntu-24-04
 
+# luarocks is needed for running lua projects in oss-fuzz.
 RUN apt-get update && apt-get install -y luarocks
 
 ENV UPDATE_WEB_TESTS False