Update pip requirement from <25.3,>=21.0 to >=21.0,<25.4

Updates the requirements on [pip](https://github.com/pypa/pip) to permit the latest version.
- [Changelog](https://github.com/pypa/pip/blob/main/NEWS.rst)
- [Commits](pypa/pip@21.0...25.3)

---
updated-dependencies:
- dependency-name: pip
  dependency-version: '25.3'
  dependency-type: direct:production
...

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

Author: dependabot[bot]

requirements.txt

@@ -1,4 +1,4 @@
 colorlog==6.10.1
 homeassistant==2025.8.0
-pip>=21.0,<25.3
+pip>=21.0,<25.4
 ruff==0.14.2