patch 8.2.0140: CI does not test building doc tags

Problem:    CI does not test building doc tags.
Solution:   Add the vimtags/gcc build. Cleanup showing version. (Ozaki Kiichi,
            closes #5513)

ci/if_ver-cmd.vim

@@ -0,0 +1,12 @@
+" Provide 'PrintVer' command to print the interface versions.
+
+func s:print_ver(lang, ...)
+  if has(a:lang)
+    exec a:lang join(a:000)
+  else
+    echo 'N/A'
+  endif
+  echo ''
+endfunc
+
+command -nargs=+ PrintVer call <SID>print_ver(<f-args>)