Update Go Dockerfile to use a separate directory for caching

Author: rohitpaulk

dockerfiles/go-1.22.Dockerfile

@@ -2,6 +2,11 @@ FROM golang:1.22-alpine
 
 ENV CODECRAFTERS_DEPENDENCY_FILE_PATHS="go.mod,go.sum"
 
+# By default, Go uses $HOME for GOCACHE. We need to override $HOME in some tests,
+# so let's ensure Go uses a different directory for caching.
+RUN mkdir -p /cache
+ENV GOCACHE=/cache
+
 WORKDIR /app
 
 COPY go.mod go.sum ./