chore: remove per request dynamic parameters opt in and rely on template (#18505)

When in experimental this was used as an escape hatch. Removed to be
consistent with the template author's intentions

Backwards compatible, removing an experimental api field that is no longer used.

coderd/workspaces.go

@@ -717,10 +717,6 @@ func createWorkspace(
 			builder = builder.MarkPrebuiltWorkspaceClaim()
 		}
 
-		if req.EnableDynamicParameters {
-			builder = builder.DynamicParameters(req.EnableDynamicParameters)
-		}
-
 		workspaceBuild, provisionerJob, provisionerDaemons, err = builder.Build(
 			ctx,
 			db,