Bump paddlepaddle in /examples/tutorials/parl2_dygraph

Bumps [paddlepaddle](https://github.com/paddlepaddle/paddle) from 2.2.0 to 2.6.1.
- [Release notes](https://github.com/paddlepaddle/paddle/releases)
- [Changelog](https://github.com/PaddlePaddle/Paddle/blob/develop/RELEASE.md)
- [Commits](PaddlePaddle/Paddle@v2.2.0...v2.6.1)

---
updated-dependencies:
- dependency-name: paddlepaddle
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

examples/tutorials/parl2_dygraph/requirements.txt

@@ -1,5 +1,5 @@
 # requirements for tutorials (paddle dygraph version)
-paddlepaddle==2.2.0
+paddlepaddle==2.6.1
 parl==2.0.3
 gym==0.18.0
 atari-py==0.2.6