Bump to golang 1.20 to pick up go1.19.6 / go1.20.1 CVE fixes

Go 1.18 is already EOL and doesn't have fixes available.

Signed-off-by: Jingyuan Liang <jingyuanliang@google.com>

.github/workflows/test.yaml

@@ -4,7 +4,7 @@ name: test
 on: ["push", "pull_request"]
 
 env:
-  GO_VERSION: "1.18"
+  GO_VERSION: "1.20"
   LINUX_ARCHES: "amd64 386 arm arm64 s390x mips64le ppc64le riscv64"
 
 jobs:

go.mod

@@ -1,6 +1,6 @@
 module github.com/containernetworking/plugins
 
-go 1.18
+go 1.20
 
 require (
 	github.com/Microsoft/hcsshim v0.9.8

scripts/release.sh

@@ -16,7 +16,7 @@ rm -Rf ${SRC_DIR}/${RELEASE_DIR}
 mkdir -p ${SRC_DIR}/${RELEASE_DIR}
 mkdir -p ${OUTPUT_DIR}
 
-$DOCKER run -ti -v ${SRC_DIR}:/go/src/github.com/containernetworking/plugins:z --rm golang:1.18-alpine \
+$DOCKER run -ti -v ${SRC_DIR}:/go/src/github.com/containernetworking/plugins:z --rm golang:1.20-alpine \
 /bin/sh -xe -c "\
     apk --no-cache add bash tar;
     cd /go/src/github.com/containernetworking/plugins; umask 0022;