Handle 'go get' deprecation (#14611)

* Switch out 'go get' for 'go install'.

* Changelog

.ci/scripts/setup_complement_prerequisites.sh

@@ -21,7 +21,7 @@ endblock
 
 block Install Complement Dependencies
   sudo apt-get -qq update && sudo apt-get install -qqy libolm3 libolm-dev
-  go get -v github.com/gotesttools/gotestfmt/v2/cmd/gotestfmt@latest
+  go install -v github.com/gotesttools/gotestfmt/v2/cmd/gotestfmt@latest
 endblock
 
 block Install custom gotestfmt template

changelog.d/14611.misc

@@ -0,0 +1 @@
+Switch to Go recommended installation method for `gotestfmt` template in CI.