pip prod(deps): update cgen requirement

Updates the requirements on [cgen](https://github.com/inducer/cgen) to permit the latest version.
- [Commits](inducer/cgen@v2020.1...v2025.1)

---
updated-dependencies:
- dependency-name: cgen
  dependency-version: '2025.1'
  dependency-type: direct:production
...

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

Author: dependabot[bot]

requirements.txt

@@ -3,7 +3,7 @@ numpy>=1.26,<=2.4.3
 sympy>=1.12.1,<1.15
 psutil>=5.1.0,<8.0
 py-cpuinfo<10
-cgen>=2020.1,<2026
+cgen>=2025.1,<2026
 codepy>=2019.1,<2025
 multidict<6.3
 anytree>=2.4.3,<=2.13.0