chore: remove nixpkgs-pgbackrest input

Author: yvan-sraka

flake.lock

@@ -22,7 +22,6 @@
     nix2container.inputs.nixpkgs.follows = "nixpkgs";
     nix2container.url = "github:nlewo/nix2container";
     nixpkgs-go124.url = "github:Nixos/nixpkgs/d2ac4dfa61fba987a84a0a81555da57ae0b9a2b0";
-    nixpkgs-pgbackrest.url = "github:nixos/nixpkgs/nixos-unstable-small";
     nixpkgs.url = "https://channels.nixos.org/nixos-unstable/nixexprs.tar.xz";
     rust-overlay.inputs.nixpkgs.follows = "nixpkgs";
     rust-overlay.url = "github:oxalica/rust-overlay";

flake.nix

@@ -40,7 +40,7 @@
           migrate-tool = pkgs.callPackage ./migrate-tool.nix { psql_15 = self'.packages."psql_15/bin"; };
           overlayfs-on-package = pkgs.callPackage ./overlayfs-on-package.nix { };
           packer = pkgs.callPackage ./packer.nix { inherit inputs; };
-          pg-backrest = inputs.nixpkgs-pgbackrest.legacyPackages.${pkgs.system}.pgbackrest;
+          pg-backrest = inputs.nixpkgs.legacyPackages.${pkgs.system}.pgbackrest;
           pg-restore = pkgs.callPackage ./pg-restore.nix { psql_15 = self'.packages."psql_15/bin"; };
           pg_prove = pkgs.perlPackages.TAPParserSourceHandlerpgTAP;
           pg_regress = makePgRegress activeVersion;