maintainers: update all-maintainers.nix

Automated update of the master maintainers list combining:
- Home Manager specific maintainers from modules/lib/maintainers.nix
- Nixpkgs maintainers referenced in Home Manager modules

**Added:** 0 maintainers
**Removed:** 1 maintainers
**Total:** 298 → 297 maintainers

**❌ Removed:** SebTM

Generated by: lib/python/generate-all-maintainers.py

all-maintainers.nix

@@ -405,13 +405,6 @@
     name = "Sefa Eyeoglu";
     source = "nixpkgs";
   };
-  SebTM = {
-    email = "mail@sebastian-sellmeier.de";
-    github = "SebTM";
-    githubId = 17243347;
-    name = "Sebastian Sellmeier";
-    source = "nixpkgs";
-  };
   ShamrockLee = {
     email = "shamrocklee@posteo.net";
     github = "ShamrockLee";