build: bump minimal go version to 1.22

Author: buchdag

.github/workflows/assets.yml

@@ -17,7 +17,7 @@ jobs:
 
       - uses: actions/setup-go@v5
         with:
-          go-version: "1.21"
+          go-version-file: go.mod
 
       - name: Build release assets
         run: make release

go.mod

@@ -1,6 +1,6 @@
 module github.com/nginx-proxy/docker-gen
 
-go 1.21.0
+go 1.22.0
 
 require (
 	github.com/BurntSushi/toml v1.3.2