Bump sentencepiece from 0.2.0 to 0.2.1 in /py

Bumps [sentencepiece](https://github.com/google/sentencepiece) from 0.2.0 to 0.2.1.
- [Release notes](https://github.com/google/sentencepiece/releases)
- [Commits](google/sentencepiece@v0.2.0...v0.2.1)

---
updated-dependencies:
- dependency-name: sentencepiece
  dependency-version: 0.2.1
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

py/requirements.txt

@@ -5,4 +5,4 @@ mdurl==0.1.2
 protobuf==5.26.1
 Pygments==2.17.2
 rich==13.7.1
-sentencepiece==0.2.0
+sentencepiece==0.2.1