Bump py7zr from 0.20.6 to 0.21.0 in /tests/UDKTests

Bumps [py7zr](https://github.com/miurahr/py7zr) from 0.20.6 to 0.21.0.
- [Release notes](https://github.com/miurahr/py7zr/releases)
- [Changelog](https://github.com/miurahr/py7zr/blob/master/docs/Changelog.rst)
- [Commits](miurahr/py7zr@v0.20.6...v0.21.0)

---
updated-dependencies:
- dependency-name: py7zr
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

tests/UDKTests/requirements.txt

@@ -1,6 +1,6 @@
 httpx==0.25.0
 psutil==5.9.6
-py7zr==0.20.6
+py7zr==0.21.0
 tqdm==4.66.1
 udk_configparser==1.1.1
 watchdog==3.0.0