gnu: python-gitpython: Switch to ‘git-minimal/pinned’.

This will allow updating ‘git-minimal’ and ‘git’ without triggering a
rebuild of ‘python-gitpython’ and its 3.5K dependents.

* gnu/packages/version-control.scm (python-gitpython): Depend on
‘git-minimal/pinned’ instead of ‘git’.

Change-Id: I7f635270eb915919a40ceb8f0ed2031a8749c75c

gnu/packages/version-control.scm

@@ -1658,7 +1658,7 @@ allowing to handle large objects with a small memory footprint.")
                                      (search-input-file inputs "/bin/git")
                                      "\""))))))))
     (inputs
-     (list git))
+     (list git-minimal/pinned))
     (propagated-inputs
      (list python-gitdb python-typing-extensions))
     (native-inputs