Revert "Make plugin task first-class citizen (#268)"

This reverts commit 78cd22d.

flyteidl-protos/src/main/proto/flyteidl/core/tasks.proto

@@ -59,14 +59,6 @@ message RuntimeMetadata {
 
     //+optional It can be used to provide extra information about the runtime (e.g. python, golang... etc.).
     string flavor = 3;
-
-    //+optional It can be used to provide extra information for the plugin.
-    PluginMetadata plugin_metadata = 4;
-}
-
-message PluginMetadata {
-    //+optional It can be used to decide use sync plugin or async plugin during runtime.
-    bool is_sync_plugin = 1;
 }
 
 // Task Metadata

flytekit-api/src/main/java/org/flyte/api/v1/TaskTemplate.java

@@ -22,9 +22,6 @@
 /**
  * A Task structure that uniquely identifies a task in the system. Tasks are registered as a first
  * step in the system.
- *
- * <p>FIXME: consider offering TaskMetadata instead of having everything in TaskTemplate, see
- * https://github.com/flyteorg/flyte/blob/ea72bbd12578d64087221592554fb71c368f8057/flyteidl/protos/flyteidl/core/tasks.proto#L90
  */
 @AutoValue
 public abstract class TaskTemplate {
@@ -67,9 +64,6 @@ public abstract class TaskTemplate {
    */
   public abstract boolean cacheSerializable();
 
-  /** Indicates whether to use sync plugin or async plugin to handle this task. */
-  public abstract boolean isSyncPlugin();
-
   public abstract Builder toBuilder();
 
   public static Builder builder() {
@@ -95,8 +89,6 @@ public abstract static class Builder {
 
     public abstract Builder cacheSerializable(boolean cacheSerializable);
 
-    public abstract Builder isSyncPlugin(boolean isSyncPlugin);
-
     public abstract TaskTemplate build();
   }
 }