Remove the 'fresh clone' step of the release process

We already clean the repository in step 3. Since the big split, there
are fewer complexities in the repo that can cause problems in packaging,
and I think this step is overkill.

This is part of my effort to simplify the release procedure, as I feel
like I'm spending a lot of time cutting releases nowadays.

docs/source/coredev/release_process.rst

@@ -157,20 +157,11 b' Update release.py back to ``x.y-dev`` or ``x.y-maint``, and re-add the'
     git commit -am "back to development"
     git push origin $BRANCH
 
-7. Get a fresh clone
---------------------
+Now checkout the tag we just made::
 
-Get a fresh clone of the tag for building the release::
+    git checkout $VERSION
 
-    cd /tmp
-    git clone --depth 1 https://github.com/ipython/ipython.git -b "$VERSION"
-    cd ipython
-
-.. note::
-
-    You can also cleanup the current working repository with ``git clean -xfdi``
-
-8. Run the release script
+7. Run the release script
 -------------------------
 
 Run the ``release`` script, this step requires having a current wheel, Python
@@ -194,7 +185,7 b' PyPI/Warehouse will automatically hide previous releases. If you are uploading'
 a non-stable version, make sure to log-in to PyPI and un-hide previous version.
 
 
-9. Draft a short release announcement
+8. Draft a short release announcement
 -------------------------------------
 
 The announcement should include:
@@ -209,7 +200,7 b' Post the announcement to the mailing list and or blog, and link from Twitter.'
 
     If you are doing a RC or Beta, you can likely skip the next steps.
 
-10. Update milestones on GitHub
+9. Update milestones on GitHub
 -------------------------------
 
 These steps will bring milestones up to date:
@@ -218,7 +209,7 b' These steps will bring milestones up to date:'
 - open a new milestone for the next release (x, y+1), if the milestone doesn't
   exist already
 
-11. Update the IPython website
+10. Update the IPython website
 ------------------------------
 
 The IPython website should document the new release:
@@ -227,18 +218,18 b' The IPython website should document the new release:'
 - update current version and download links
 - update links on the documentation page (especially if a major release)
 
-12. Update readthedocs
+11. Update readthedocs
 ----------------------
 
 Make sure to update readthedocs and set the latest tag as stable, as well as
 checking that previous release is still building under its own tag. 
 
-13. Update the Conda-Forge feedstock
+12. Update the Conda-Forge feedstock
 ------------------------------------
 
 Follow the instructions on `the repository <https://github.com/conda-forge/ipython-feedstock>`_
 
-14. Celebrate!
+13. Celebrate!
 --------------
 
 Celebrate the release and please thank the contributors for their work. Great