Update the Varnish container (non-klarlack) to version 6.6.0.

container/Dockerfile.varnish

 FROM centos:centos7.9.2009
 
-COPY varnishcache_varnish65.repo /etc/yum.repos.d/
+COPY varnishcache_varnish66.repo /etc/yum.repos.d/
 COPY uplex_varnish.repo /etc/yum.repos.d/
 
 # yum update with --exclude=shadow-utils because the cap_set_file
@@ -8,11 +8,11 @@ COPY uplex_varnish.repo /etc/yum.repos.d/
 # docker build.
 RUN yum install -y -q epel-release && yum -q makecache -y fast && \
     yum update -y -q --exclude=shadow-utils && \
-    yum install -y -q varnish-6.5.1 && \
-    yum install -y -q --nogpgcheck vmod-re2-1.10.0 && \
-    yum install -y -q --nogpgcheck vmod-selector-2.5.0 && \
-    yum install -y -q --nogpgcheck vmod-dynamic-2.3.0 && \
-    yum install -y -q --nogpgcheck vmod-blobdigest-1.5.0 && \
+    yum install -y -q varnish-6.6.0 && \
+    yum install -y -q --nogpgcheck vmod-re2-2.0.0 && \
+    yum install -y -q --nogpgcheck vmod-selector-2.6.0 && \
+    yum install -y -q --nogpgcheck vmod-dynamic-2.4.0 && \
+    yum install -y -q --nogpgcheck vmod-blobdigest-1.6.0 && \
     yum -q clean all && rm -rf /var/cache/yum && rm -rf /usr/share/man && \
     rm -rf /usr/share/doc && rm /etc/varnish/*
 

container/varnishcache_varnish65.repo → container/varnishcache_varnish66.repo

-[varnishcache_varnish65]
-name=varnishcache_varnish65
-baseurl=https://packagecloud.io/varnishcache/varnish65/el/7/$basearch
+[varnishcache_varnish66]
+name=varnishcache_varnish66
+baseurl=https://packagecloud.io/varnishcache/varnish66/el/7/$basearch
 repo_gpgcheck=1
 gpgcheck=0
 enabled=1
-gpgkey=https://packagecloud.io/varnishcache/varnish65/gpgkey
+gpgkey=https://packagecloud.io/varnishcache/varnish66/gpgkey
 sslverify=1
 sslcacert=/etc/pki/tls/certs/ca-bundle.crt
 metadata_expire=300
 
-[varnishcache_varnish65-source]
-name=varnishcache_varnish65-source
-baseurl=https://packagecloud.io/varnishcache/varnish65/el/7/SRPMS
+[varnishcache_varnish66-source]
+name=varnishcache_varnish66-source
+baseurl=https://packagecloud.io/varnishcache/varnish66/el/7/SRPMS
 repo_gpgcheck=1
 gpgcheck=0
 enabled=1
-gpgkey=https://packagecloud.io/varnishcache/varnish65/gpgkey
+gpgkey=https://packagecloud.io/varnishcache/varnish66/gpgkey
 sslverify=1
 sslcacert=/etc/pki/tls/certs/ca-bundle.crt
 metadata_expire=300