Update preferred version checksums

PR github#966 updated the PREFERRED_GO_VERSION from go1.14.7
to go1.16.4 but didn't updated the corresponding binary
checksums. The checksums can be found at https://go.dev/dl/

Author: staktrace

script/bootstrap

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-set -e
+set -ex
 
 # Make sure we have the version of Go we want to depend on, either from the
 # system or one we grab ourselves.

script/build

@@ -1,6 +1,6 @@
 #!/bin/bash
 
-set -e
+set -ex
 
 . script/bootstrap
 

script/ensure-go-installed

@@ -1,13 +1,15 @@
 #!/bin/bash
 
+set -x
+
 PREFERRED_GO_VERSION=go1.16.4
 SUPPORTED_GO_VERSIONS='go1.1[56]'
 
 GO_PKG_DARWIN=${PREFERRED_GO_VERSION}.darwin-amd64.pkg
-GO_PKG_DARWIN_SHA=0f215de06019a054a3da46a0722989986c956d719c7a0a8fc38a5f3c216d6f6b
+GO_PKG_DARWIN_SHA=9f9b940d0f4b3ac764f0a33d78384a87b804aab29d1aacbdc9bca3a3480e9272
 
 GO_PKG_LINUX=${PREFERRED_GO_VERSION}.linux-amd64.tar.gz
-GO_PKG_LINUX_SHA=4a7fa60f323ee1416a4b1425aefc37ea359e9d64df19c326a58953a97ad41ea5
+GO_PKG_LINUX_SHA=7154e88f5a8047aad4b80ebace58a059e36e7e2e4eb3b383127a28c711b4ff59
 
 export ROOTDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )/.." && pwd )"
 cd $ROOTDIR