RF: Remove import of GIT_SSH_COMMAND within .consts

It was added there for compatibility in 24d4631
when moved deeper in hierarchy.

I think it would be best for us to avoid deeper imports in this file and thus
to avoid possible circular imports observed in the past. Ref:
datalad#7393

datalad/consts.py

@@ -10,8 +10,8 @@
 """
 
 import os
-from os.path import join
 import re
+from os.path import join
 
 # directory containing prepared metadata of a dataset repository:
 DATALAD_DOTDIR = ".datalad"
@@ -48,9 +48,6 @@
 # Format to use for time stamps
 TIMESTAMP_FMT = "%Y-%m-%dT%H:%M:%S%z"
 
-# in order to avoid breakage, import runner-related const
-from datalad.runner.gitrunner import GIT_SSH_COMMAND
-
 # magic sha is from `git hash-object -t tree /dev/null`, i.e. from nothing
 PRE_INIT_COMMIT_SHA = '4b825dc642cb6eb9a060e54bf8d69288fbee4904'