Install git in Lmod77 container

Author: vkarak

ci-scripts/dockerfiles/reframe-lmod77.dockerfile

@@ -7,7 +7,7 @@ FROM ghcr.io/reframe-hpc/lmod:7.7
 
 # Install ReFrame unit test requirements
 RUN apt-get -y update && \
-    apt-get -y install gcc make python3 python3-pip
+    apt-get -y install gcc git make python3 python3-pip
 
 # ReFrame user
 RUN useradd -ms /bin/bash rfmuser