[CICD-29] Stop erroneous build failures due to attempt to rsync mu-plugin subdirectories

[daniel-savo]

JIRA Ticket

CICD-29

What Are We Doing Here

When adding all install files to a repository, the GHA build was failing due to rsync attempting to update the mu-plugin/wpe-cache-plugin subdirectories:

rsync: failed to set times on "/home/wpe-user/sites/dscicdtest1/wp-content/mu-plugins/wpe-cache-plugin": Operation not permitted (1)
rsync: failed to set times on "/home/wpe-user/sites/dscicdtest1/wp-content/mu-plugins/wpe-cache-plugin/css": Operation not permitted (1)
rsync: failed to set times on "/home/wpe-user/sites/dscicdtest1/wp-content/mu-plugins/wpe-cache-plugin/js": Operation not permitted (1)
rsync: failed to set times on "/home/wpe-user/sites/dscicdtest1/wp-content/mu-plugins/wpe-cache-plugin/js/components": Operation not permitted (1)
rsync: failed to set times on "/home/wpe-user/sites/***/wp-content/mu-plugins/wpe-cache-plugin/js/dist": Operation not permitted (1)
rsync: failed to set times on "/home/wpe-user/sites/***/wp-content/mu-plugins/wpe-cache-plugin/js/services": Operation not permitted (1)
rsync: failed to set times on "/home/wpe-user/sites/***/wp-content/mu-plugins/wpe-cache-plugin/js/utils": Operation not permitted (1)
rsync: failed to set times on "/home/wpe-user/sites/***/wp-content/mu-plugins/wpe-cache-plugin/security": Operation not permitted (1)
rsync: failed to set times on "/home/wpe-user/sites/***/wp-content/mu-plugins/wpe-cache-plugin/view": Operation not permitted (1)

This PR fixes the excludes paths to ensure this doesn't happen.

[marksabbath]

LGTM!