linphonePackages: remove thibaultlemaire as maintainer

As per wishes, see:
https://github.com/NixOS/nixpkgs/pull/444603#pullrequestreview-3261894742

pkgs/applications/networking/instant-messengers/linphone/bc-decaf/default.nix

@@ -37,7 +37,6 @@ stdenv.mkDerivation {
     license = lib.licenses.mit;
     maintainers = with lib.maintainers; [
       naxdy
-      thibaultlemaire
     ];
     platforms = lib.platforms.linux;
   };

pkgs/applications/networking/instant-messengers/linphone/bc-soci/default.nix

@@ -51,7 +51,6 @@ stdenv.mkDerivation {
     license = lib.licenses.boost;
     platforms = lib.platforms.all;
     maintainers = with lib.maintainers; [
-      thibaultlemaire
       naxdy
     ];
   };