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:** 2 maintainers
**Removed:** 0 maintainers
**Total:** 273 → 275 maintainers

**✅ Added:** FredeHoey, roberth

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

all-maintainers.nix

@@ -136,6 +136,13 @@
     name = "Erin Pletches";
     source = "nixpkgs";
   };
+  FredeHoey = {
+    email = "frederikbraendstrup@gmail.com";
+    github = "FredeHoey";
+    githubId = 7551358;
+    name = "Frede Emil";
+    source = "nixpkgs";
+  };
   FriedrichAltheide = {
     github = "FriedrichAltheide";
     githubId = 11352905;
@@ -1942,6 +1949,14 @@
     name = "repparw";
     source = "nixpkgs";
   };
+  roberth = {
+    email = "nixpkgs@roberthensing.nl";
+    github = "roberth";
+    githubId = 496447;
+    matrix = "@roberthensing:matrix.org";
+    name = "Robert Hensing";
+    source = "nixpkgs";
+  };
   robwalt = {
     email = "robwalter96@gmail.com";
     github = "robwalt";