Bump notebook from 6.4.10 to 6.4.12 in /binder

Bumps [notebook](http://jupyter.org) from 6.4.10 to 6.4.12.

---
updated-dependencies:
- dependency-name: notebook
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

binder/requirements.txt

@@ -36,7 +36,7 @@ nbclient==0.5.13
 nbconvert==6.4.5
 nbformat==5.3.0
 nest-asyncio==1.5.5
-notebook==6.4.10
+notebook==6.4.12
 packaging==21.3
 pandocfilters==1.5.0
 parso==0.8.3