chore: Prep for 0.14.0 release (#2514)

* chore: Prep for 0.14 release in docs and ci

* chore: Update kubeconform versions

* chore: Update to pyrra v0.7 for add-on

* chore: Drop deprecated apiserver_flowcontrol_request_concurrency_in_use metric

.github/workflows/ci.yaml

@@ -83,8 +83,9 @@ jobs:
     strategy:
       matrix:
         kind-image:
-          - 'kindest/node:v1.30.0'
+          - 'kindest/node:v1.31.0'
           - 'kindest/node:v1.30.4'
+          - 'kindest/node:v1.29.8'
     steps:
     - uses: actions/checkout@v4
       with: