Add gha-token tool

This tool is needed to issue temporary GH tokens (for example for GH
CLI) via App Credentials

Author: adidenko

Dockerfile

@@ -2,6 +2,11 @@
 # Image with Github tools
 #
 
+###### Build gha-token tool
+FROM golang:1.24.4-alpine3.21 AS build
+RUN go install github.com/slawekzachcial/gha-token@1.1.0
+
+###### Final image
 FROM alpine:3.21
 
 RUN apk add --no-cache git github-cli bash openssh curl \
@@ -11,6 +16,7 @@ RUN apk add --no-cache git github-cli bash openssh curl \
     && chmod 700 /home/git/.ssh
 
 ADD files/known_hosts /home/git/.ssh/known_hosts
+COPY --from=build /go/bin/gha-token /usr/bin/gha-token
 
 WORKDIR /home/git
 USER 1100