Mark disable-affinity-assistant as deprecated

This commit marks the `disable-affinity-assistant` feature flag as deprecated in favor of the new `coschedule` feature flag.
See migration plan in https://github.com/tektoncd/pipeline/blob/main/docs/affinityassistants.md

/kind misc

config/config-feature-flags.yaml

@@ -29,6 +29,8 @@ data:
   # See more in the Affinity Assistant documentation
   # https://github.com/tektoncd/pipeline/blob/main/docs/affinityassistants.md
   # or https://github.com/tektoncd/pipeline/pull/2630 for more info.
+  #
+  # Note: This feature flag is deprecated and will be removed in 9 months. Consider using `coschedule` feature flag to configure Affinity Assistant behavior.
   disable-affinity-assistant: "false"
   # Setting this flag will determine how PipelineRun Pods are scheduled with Affinity Assistant.
   # Acceptable values are "workspaces" (default), "pipelineruns", "isolate-pipelinerun", or "disabled".
@@ -41,7 +43,6 @@ data:
   #
   # See more in the Affinity Assistant documentation
   # https://github.com/tektoncd/pipeline/blob/main/docs/affinityassistants.md
-  # NOTE: this feature is still under development and not yet functional.
   coschedule: "workspaces"
   # Setting this flag to "true" will prevent Tekton scanning attached
   # service accounts and injecting any credentials it finds into your

docs/additional-configs.md

@@ -215,6 +215,8 @@ The flags in this ConfigMap are as follows:
   The Affinity Assistant is incompatible with other affinity rules
   configured for `TaskRun` pods.
 
+  **Note:** This feature flag is deprecated and will be removed in 9 months. Consider using `coschedule` feature flag to configure Affinity Assistant behavior.
+
   **Note:** Affinity Assistant use [Inter-pod affinity and anti-affinity](https://kubernetes.io/docs/concepts/scheduling-eviction/assign-pod-node/#inter-pod-affinity-and-anti-affinity)
   that require substantial amount of processing which can slow down scheduling in large clusters
   significantly. We do not recommend using them in clusters larger than several hundred nodes

docs/affinityassistants.md

@@ -29,7 +29,8 @@ configured for the `TaskRun` pods (i.e. other affinity rules specified in custom
 If the `PipelineRun` has a custom [PodTemplate](pipelineruns.md#specifying-a-pod-template) configured, the `NodeSelector` and `Tolerations` fields will also be set on the Affinity Assistant pod. The Affinity Assistant
 is deleted when the `PipelineRun` is completed. 
 
-Currently, the Affinity Assistant Modes can be configured by the `disable-affinity-assistant` and `coschedule` feature flags. In 9 months, the `disable-affinity-assistant` feature flag will be deprecated, and the Affinity Assistant Modes will be only determined by the `coschedule` feature flag. 
+Currently, the Affinity Assistant Modes can be configured by the `disable-affinity-assistant` and `coschedule` feature flags. 
+The `disable-affinity-assistant` feature flag is now deprecated and will be removed in 9 month. At the time, the Affinity Assistant Modes will be only determined by the `coschedule` feature flag. 
 
 The following chart summarizes the Affinity Assistant Modes with different combinations of the `disable-affinity-assistant` and `coschedule` feature flags during migration (when both feature flags are present) and after the migration (when only the `coschedule` flag is present).
 

docs/deprecations.md

@@ -27,6 +27,7 @@ The following features are deprecated but have not yet been removed.
 | [The `config-trusted-resources` configMap is deprecated](https://github.com/tektoncd/pipeline/issues/5852)                                                                                                                 | v0.45.0                                                              | Alpha                                                                                                  | v0.46.0                       |
 | [The `default-cloud-events-sink` setting in the `config-defaults` configMap is deprecated](https://github.com/tektoncd/pipeline/pull/6883) in favour of the new `config-events` configMap.                                                                                                                | v0.50.0                                                              | N/A                                                                                                  | v0.59.0                       |
 | [v1beta1 Tasks, TaskRuns, Pipelines, and PipelineRuns are deprecated in favor of v1](https://github.com/tektoncd/pipeline/issues/5541)                                                                                                                 | v0.50.0                                                              | Beta                                                                                                  | v0.62.0                       |
+| [The `disable-affinity-assistant` feature flag is deprecated in favor of the `coschedule` feature flag](https://github.com/tektoncd/pipeline/issues/6988)                                                                                                                 | v0.51.0                                                              | N/A                                                                                                  | April 27, 2024                       |
 
 ### v1beta1 deprecation