Bump paddlepaddle from 2.6.2 to 3.1.1 in /tests

Bumps [paddlepaddle](https://github.com/paddlepaddle/paddle) from 2.6.2 to 3.1.1.
- [Release notes](https://github.com/paddlepaddle/paddle/releases)
- [Changelog](https://github.com/PaddlePaddle/Paddle/blob/develop/RELEASE.md)
- [Commits](PaddlePaddle/Paddle@v2.6.2...v3.1.1)

---
updated-dependencies:
- dependency-name: paddlepaddle
  dependency-version: 3.1.1
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

tests/constraints.txt

@@ -13,7 +13,7 @@ defusedxml>=0.7.1
 tensorflow>=2.5,<2.20.0
 requests>=2.25.1
 opencv-python>=4.5
-paddlepaddle==2.6.2
+paddlepaddle==3.1.1
 protobuf>=3.18.1,<7.0.0
 py>=1.9.0
 pytest>=5.0,<8.5