removal(flux-system): Drop tf-controller

It's currently not used, so why keep it around?

infrastructure/base/flux-system/kustomization.yaml

@@ -3,6 +3,5 @@ kind: Kustomization
 namespace: flux-system
 resources:
   - alerts.yaml
-  - tf-controller.yaml
 components:
   - monitoring

infrastructure/base/flux-system/tf-controller.yaml

----
-apiVersion: source.toolkit.fluxcd.io/v1beta2
-kind: HelmRepository
-metadata:
-  name: tf-controller
-  namespace: flux-system
-spec:
-  interval: 30m
-  url: https://weaveworks.github.io/tf-controller/
----
-apiVersion: helm.toolkit.fluxcd.io/v2beta2
-kind: HelmRelease
-metadata:
-  name: tf-controller
-  namespace: flux-system
-spec:
-  releaseName: tf-controller
-  chart:
-    spec:
-      chart: tf-controller
-      sourceRef:
-        kind: HelmRepository
-        name: tf-controller
-        namespace: flux-system
-      version: 0.15.1
-  interval: 5m
-  install:
-    crds: CreateReplace
-  upgrade:
-    crds: CreateReplace