Improve git-vs-tarball detection (#1423)

* Extract version from directory name if .git dir is missing

* Avoid using shell

* Remove .gitinfo build from pipeline

* Fix git-detecting rule to be robust in presence of setup-git

Makefile

@@ -1,7 +1,7 @@
 GO_VERSION=$(shell grep "^go " go.mod | cut -f 2 -d ' ')
 NODE_VERSION=$(shell cat .nvmrc)
 
-ifneq ("$(wildcard .git)","")
+ifneq ("$(wildcard .git/HEAD)","")
 GIT_SHA=$(shell git rev-parse --short HEAD)
 GIT_TAG=$(shell git describe --tags `git rev-list --tags --max-count=1`)
 else