Re-patch yum repos

.github/workflows/llvm-build/centos.Dockerfile

@@ -16,6 +16,12 @@ RUN sed -i s/^mirrorlist=http/#mirrorlist=http/g /etc/yum.repos.d/*.repo
 
 # Install build dependencies
 RUN yum install --assumeyes centos-release-scl
+
+# The definition of insanity is doing the same thing and expecting a different result
+RUN sed -i s/mirror.centos.org/vault.centos.org/g /etc/yum.repos.d/*.repo
+RUN sed -i s/^#.*baseurl=http/baseurl=http/g /etc/yum.repos.d/*.repo
+RUN sed -i s/^mirrorlist=http/#mirrorlist=http/g /etc/yum.repos.d/*.repo
+
 RUN yum install --assumeyes --nogpgcheck llvm-toolset-13.0
 RUN yum install --assumeyes rh-python38-python-devel rh-python38-python-pip
 SHELL [ "/usr/bin/scl", "enable", "llvm-toolset-13.0", "rh-python38" ]