[chore]: Bump github.com/spf13/viper from 1.19.0 to 1.20.0

Bumps [github.com/spf13/viper](https://github.com/spf13/viper) from 1.19.0 to 1.20.0.
- [Release notes](https://github.com/spf13/viper/releases)
- [Commits](https://github.com/spf13/viper/compare/v1.19.0...v1.20.0)

---
updated-dependencies:
- dependency-name: github.com/spf13/viper
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

vendor/github.com/go-viper/mapstructure/v2/flake.nix

@@ -0,0 +1,39 @@
+{
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    flake-parts.url = "github:hercules-ci/flake-parts";
+    devenv.url = "github:cachix/devenv";
+  };
+
+  outputs = inputs@{ flake-parts, ... }:
+    flake-parts.lib.mkFlake { inherit inputs; } {
+      imports = [
+        inputs.devenv.flakeModule
+      ];
+
+      systems = [ "x86_64-linux" "x86_64-darwin" "aarch64-darwin" ];
+
+      perSystem = { config, self', inputs', pkgs, system, ... }: rec {
+        devenv.shells = {
+          default = {
+            languages = {
+              go.enable = true;
+            };
+
+            pre-commit.hooks = {
+              nixpkgs-fmt.enable = true;
+            };
+
+            packages = with pkgs; [
+              golangci-lint
+            ];
+
+            # https://github.com/cachix/devenv/issues/528#issuecomment-1556108767
+            containers = pkgs.lib.mkForce { };
+          };
+
+          ci = devenv.shells.default;
+        };
+      };
+    };
+}