TUN-8072: Add script to download cloudflare go for Mac build agents

.teamcity/mac/build.sh

@@ -143,7 +143,7 @@ if [[ ! -z "$CODE_SIGN_NAME" ]]; then
   codesign -s "${CODE_SIGN_NAME}" -f -v --timestamp --options runtime ${BINARY_NAME}
   
  # notarize the binary
- # TODO: https://jira.cfdata.org/browse/TUN-5789
+ # TODO: TUN-5789
 fi
 
 # creating build directory
@@ -169,7 +169,7 @@ if [[ ! -z "$PKG_SIGN_NAME" ]]; then
       ${PKGNAME}
 
       # notarize the package
-      # TODO: https://jira.cfdata.org/browse/TUN-5789
+      # TODO: TUN-5789
 else
     pkgbuild --identifier com.cloudflare.${PRODUCT} \
       --version ${VERSION} \

.teamcity/mac/install-cloudflare-go.sh

@@ -0,0 +1,11 @@
+cd /tmp/
+git clone -q https://github.com/cloudflare/go
+cd go/src
+# https://github.com/cloudflare/go/tree/34129e47042e214121b6bbff0ded4712debed18e is version go1.21.5-devel-cf
+git checkout -q 34129e47042e214121b6bbff0ded4712debed18e
+./make.bash
+
+export PATH="/tmp/go/bin:$PATH"
+go version
+which go
+go env