fix(ci): fix staging Dockerfile (#2474)

Author: timwu20

Dockerfile.staging

@@ -18,7 +18,7 @@ RUN ["sh", "-c", "mv .github/workflows/staging/openmetrics.d/${chain}-conf.yaml
 RUN service datadog-agent start
 
 RUN go get ./...
-RUN go build github.com/ChainSafe/gossamer/cmd/gossamer
+RUN go install -trimpath github.com/ChainSafe/gossamer/cmd/gossamer
 
 RUN ["sh", "-c", "gossamer init --chain=${chain}"]
 ENTRYPOINT ["sh", "-c", "service datadog-agent restart && gossamer --chain=${chain} --basepath=${basepath}/${chain} --publish-metrics --metrics-address=\":9876\" --pprofserver --pprofaddress=\":6060\""]