What should I be prepared for in version 21?

[wuarmin]

Hey,
can somebody please help me. I just upgraded to latest nx in my pnpm-monorepo. I use nx just as task-runner and use the caching-feature

Here's my nx.json.

{
  "affected": {
    "defaultBase": "main"
  },
  "npmScope": "@my-scope",
  "tasksRunnerOptions": {
    "default": {
      "runner": "nx/tasks-runners/default"
    }
  },
  "targetDefaults": {
    "build": {
      "cache": true,
      "dependsOn": [
        "^build"
      ]
    },
    "start": {
      "dependsOn": [
        "^build"
      ]
    }
  },
  "namedInputs": {
    "default": [
      "{projectRoot}/**/*",
      "sharedGlobals"
    ],
    "sharedGlobals": [
      "{workspaceRoot}/pnpm-workspace.yaml",
      "{workspaceRoot}/pnpm-lock.yaml",
      "{workspaceRoot}/nx.json"
    ],
    "production": [
      "default"
    ]
  }
}

Now I get:

Custom task runners will no longer be supported in Nx 21.

if I run i.e. pnpm nx build my-frontend. I don't quite understand what the customTaskRunner-options have to do with caching. If I do not want to move to a cloud-cache, I can use @nx/powerpack-shared-fs-cache as described here:
https://nx.dev/deprecated/legacy-cache

Am I wrong? If I remove the tasksRunnerOptions from my nx.json, the deprecation warning is not shown and the caching works as expected.

For my simple setting, it makes no sense at all to rely on a cloud solution. I am a single user. But I need the caching feature.
What should I be prepared for in version 21?

Thanks