[PMK-6474] : [Luigi v0.4.4] Restrict TLS cipher suites for kube-rbac-proxy container

[cruizen]

Backport of #213 to Luigi v0.4.4 for PMK 5.7

• Also backported changes to Makefile in Luigi v0.5.6

• golang update to 1.21 and Alpine version update

• Published image platform9/luigi-plugins:v0.4.4

• Published image platform9/hostplumber:v0.4.4

• Set GOFLAGS=-buildvcs=false for make test to pass

• Restrict setup-envtest to a pinned version since latest was failing (latest seems to require go 1.22)

• Also contains backport of #211