chore: update go version and update entrypoint

Author: jiaxin-ge

Dockerfile.lambda

@@ -1,5 +1,5 @@
 # Fetch or build all required binaries
-FROM golang:1.19 as builder
+FROM golang:1.20 as builder
 
 ARG VERSION_REF
 RUN test -n "${VERSION_REF}"
@@ -42,6 +42,6 @@ COPY --from=builder \
     /usr/local/bin/kubeapply \
     /usr/local/bin/
 
-COPY --from=builder /usr/local/bin/kubeapply-lambda /var/task/kubeapply-lambda
+COPY --from=builder /usr/local/bin/kubeapply-lambda /kubeapply-lambda
 
-CMD [ "kubeapply-lambda" ]
+ENTRYPOINT [ "/kubeapply-lambda" ]

go.mod

@@ -1,6 +1,6 @@
 module github.com/segmentio/kubeapply
 
-go 1.18
+go 1.20
 
 require (
 	github.com/Masterminds/semver/v3 v3.1.1