CI: test and update ci image, codeowners (#8142)

* CI: prep for the new ff deployment

* CI: variable for CI image

* git: add CI team and remove Max from CODEOWNERS

* CI: diener should be updated in CI image, not here.

* CI: diener should be updated in CI image, not here.

* CI: run cargo deny on changes to manifests and lock; run build jobs on schedules [skip ci]

* CI: remove flaming-fir deployment, it will be handled from s3 updates [skip ci]

* CI: trigger simnet with a certain substrate version

* CI: remove cargo-audit in favor of cargo-deny; prepare for being triggered

* CI: prepare to be triggered

* CI: chore

substrate/docs/CODEOWNERS

@@ -18,6 +18,11 @@
 #   are more recognizable on GitHub, you can use them for mentioning unlike an email.
 # - The latest matching rule, if multiple, takes precedence.
 
+# CI
+/.maintain/ @paritytech/ci
+/.github/ @paritytech/ci
+/.gitlab-ci.yml @paritytech/ci
+
 # Block production
 /client/basic-authorship/ @NikVolf
 
@@ -56,10 +61,3 @@
 
 # Transaction weight stuff
 /frame/support/src/weights.rs @shawntabrizi
-
-# Authority discovery
-/client/authority-discovery/ @mxinden
-/frame/authority-discovery/ @mxinden
-
-# Prometheus endpoint
-/utils/prometheus/ @mxinden