fix(core): update custom task runner deprecation message (#30093)

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## Current Behavior
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## Expected Behavior
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## Related Issue(s)
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Fixes #

docs/generated/devkit/NxJsonConfiguration.md

@@ -271,7 +271,7 @@ Dependencies between different target names across all projects
 
 **`Deprecated`**
 
-Custom task runners will no longer be supported in Nx 21. Use Nx Cloud or Nx Powerpack instead.
+Custom task runners will be replaced by a new API starting with Nx 21. More info: https://nx.dev/deprecated/custom-tasks-runner
 Available Task Runners for Nx to use
 
 #### Index signature

docs/generated/devkit/Workspace.md

@@ -371,7 +371,7 @@ Dependencies between different target names across all projects
 
 **`Deprecated`**
 
-Custom task runners will no longer be supported in Nx 21. Use Nx Cloud or Nx Powerpack instead.
+Custom task runners will be replaced by a new API starting with Nx 21. More info: https://nx.dev/deprecated/custom-tasks-runner
 Available Task Runners for Nx to use
 
 #### Index signature

packages/nx/src/config/nx-json.ts

@@ -417,7 +417,7 @@ export interface NxJsonConfiguration<T = '*' | string[]> {
     appsDir?: string;
   };
   /**
-   * @deprecated Custom task runners will no longer be supported in Nx 21. Use Nx Cloud or Nx Powerpack instead.
+   * @deprecated Custom task runners will be replaced by a new API starting with Nx 21. More info: https://nx.dev/deprecated/custom-tasks-runner
    * Available Task Runners for Nx to use
    */
   tasksRunnerOptions?: {

packages/nx/src/tasks-runner/run-command.ts

@@ -828,10 +828,9 @@ export function getRunner(
   try {
     if (isCustomRunnerPath(modulePath)) {
       output.warn({
-        title: `Custom task runners will no longer be supported in Nx 21.`,
+        title: `Custom task runners will be replaced by a new API starting with Nx 21.`,
         bodyLines: [
-          `Use Nx Cloud or the Nx Powerpack caches instead.`,
+          `For more information, see https://nx.dev/deprecated/custom-tasks-runner`,
-          `For more information, see https://nx.dev/nx-enterprise/powerpack/custom-caching`,
         ],
       });
     }

packages/nx/src/utils/command-line-utils.ts

@@ -16,7 +16,7 @@ export interface NxArgs {
   targets?: string[];
   configuration?: string;
   /**
-   * @deprecated Custom task runners will no longer be supported in Nx 21. Use Nx Cloud or Nx Powerpack instead.
+   * @deprecated Custom task runners will be replaced by a new API starting with Nx 21. More info: https://nx.dev/deprecated/custom-tasks-runner
    */
   runner?: string;
   parallel?: number;