chore: test missing dots in included labels

Author: shinsenter

test/__snapshots__/INCLUDE/include_envvars.expected.dockerfile

@@ -85,7 +85,7 @@ ENV SPACED_KEY="parsed"
 # DOCKERFILE-X:END file="./inc/custom-envs.env" includedBy="issue3.dockerfile" includeType="include"
 # include custom args from external file
 # DOCKERFILE-X:START file="./inc/custom-labels.env" includedBy="issue3.dockerfile" includeType="include"
-LABEL orgopencontainersimagesource="https://github.com/example/repo"
-LABEL orgopencontainersimagerevision="0123456789"
+LABEL org.opencontainers.image.source="https://github.com/example/repo"
+LABEL org.opencontainers.image.revision="0123456789"
 # DOCKERFILE-X:END file="./inc/custom-labels.env" includedBy="issue3.dockerfile" includeType="include"
 ENTRYPOINT [ "/bin/sh", "-c", "env" ]