Fixed situations in which cwd was specified as a relative path and used with (default) commitMode: git-cli (#486)

* fix: use latest ghcommit and fix cwd for git-cli

- `cwd` was not working correctly when commitMode was set to `git-cli`,
  as it was attempting to resolve the `cwd` twice.
  (This problem only occured when specifying a relative path for `cwd`.)
- Update `ghcommit`, and avoid calling `process.chdir()` to change the
  working directory. Instead, we now pass the `cwd` option everywhere.

fixes #475

* simplify

* Apply suggestions from code review

---------

Co-authored-by: Mateusz Burzyński <mateuszburzynski@gmail.com>

src/git.ts

@@ -117,7 +117,7 @@ export class Git {
         base: {
           commit: github.context.sha,
         },
-        addFromDirectory,
+        cwd: this.cwd,
         force: true,
       });
     }