.tool-versions(uv) uv 0.7.9 -> 0.7.12, python 3.13.4 and others

Also remove python 3.7 and 3.8 (EOL)

See also:
- uv:
  - https://github.com/astral-sh/uv/releases/tag/0.7.12
  - https://github.com/astral-sh/uv/blob/0.7.12/CHANGELOG.md
- python:
  - https://docs.python.org/release/3.13.4/whatsnew/changelog.html#python-3-13-4
  - https://devguide.python.org/versions/

Author: tony

.tool-versions

@@ -1,2 +1,2 @@
-uv 0.7.9
-python 3.13.3 3.12.10 3.11.12 3.10.17 3.9.22 3.8.20 3.7.17
+uv 0.7.12
+python 3.13.4 3.12.11 3.11.13 3.10.18 3.9.23