Fix Docker builds after upgrade to 1.23 (#153)

CONTRIBUTING.md

@@ -27,7 +27,7 @@ sudo /opt/metrikad/metrikad-{protocol} --version
 ### Development environment
 To work on an agent development you will need:
 * GNU `make`
-* Go `1.18` or later
+* Go `1.23` or later
 
 To ensure everything is set up correctly, simply run `make build`, which should build every metrika agent binary version for your architecture.
 
@@ -52,4 +52,4 @@ Exporters can be implemented to encode the data in any desirable format and prod
 
 `exporter.HandleMessage()` method will be called for every Message (Metric or Event) arriving from the Agent watchers. If the exporter implementation cannot keep up with the data flow, newly collected Messages will eventually be dropped. As such, it's recommended to implement buffering in the exporter implementation.
 
-Exporters are implemented under [contrib](internal/pkg/contrib) package, and an exporter constructor must be registered with `ExportersMap` variable in [exporter.go](internal/pkg/contrib/exporter.go).
+Exporters are implemented under [contrib](internal/pkg/contrib) package, and an exporter constructor must be registered with `ExportersMap` variable in [exporter.go](internal/pkg/contrib/exporter.go).

docker/Dockerfile

@@ -1,8 +1,8 @@
 # syntax=docker/dockerfile:1
-FROM --platform=$BUILDPLATFORM golang:1.18.6 as builder-amd64
+FROM --platform=$BUILDPLATFORM golang:1.22.6 as builder-amd64
 ENV CC "gcc"
 
-FROM --platform=$BUILDPLATFORM golang:1.18.6 as builder-arm64
+FROM --platform=$BUILDPLATFORM golang:1.22.6 as builder-arm64
 ENV CC "aarch64-linux-gnu-gcc"
 ENV CGO_ENABLED "1"