Bump psycopg2 in /{{cookiecutter.project_slug}}/backend (#129)

Bumps [psycopg2](https://github.com/psycopg/psycopg2) from 2.8.5 to 2.8.6.
- [Release notes](https://github.com/psycopg/psycopg2/releases)
- [Changelog](https://github.com/psycopg/psycopg2/blob/master/NEWS)
- [Commits](https://github.com/psycopg/psycopg2/commits)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Author: dependabot-preview[bot]

{{cookiecutter.project_slug}}/backend/requirements.txt

@@ -7,7 +7,7 @@ httpx==0.15.5
 ipython==7.18.1
 itsdangerous==1.1.0
 Jinja2==2.11.2
-psycopg2==2.8.5
+psycopg2==2.8.6
 pytest==6.1.0
 requests==2.24.0
 SQLAlchemy==1.3.19