Delete /home/ue4/.epic after building UnrealVersionSelector as well

Note that we don't need to delete the directory after the code that builds ShaderCompileWorker with `-SkipBuild`, since that code path only runs when BuildUBT.sh isn't present, and all of the engine versions with problematic UBA behaviour already include BuildUBT.sh.

Author: adamrehn

src/ue4docker/dockerfiles/ue4-minimal/linux/Dockerfile

@@ -41,7 +41,8 @@ RUN {% if build_secret_vars %}{% for var in build_secret_vars %}--mount=type=sec
 	rm -R -f /home/ue4/.epic
 
 # Ensure UnrealVersionSelector is built, since the prebuilt binaries may not be up-to-date
-RUN ./Engine/Build/BatchFiles/Linux/Build.sh UnrealVersionSelector Linux Shipping {{ standalone_build_args }}
+RUN ./Engine/Build/BatchFiles/Linux/Build.sh UnrealVersionSelector Linux Shipping {{ standalone_build_args }} && \
+	rm -R -f /home/ue4/.epic
 
 # Copy InstalledBuild.txt from the Installed Build and run UnrealVersionSelector to populate Install.ini with any custom Build ID specified in the BuildGraph flags
 # (Note that the `-unattended` flag used below requires Unreal Engine 4.22 or newer, so this will break under older versions)