Bump alembic from 1.5.3 to 1.5.8

Bumps [alembic](https://alembic.sqlalchemy.org) from 1.5.3 to 1.5.8.

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

Author: dependabot-preview[bot]

poetry.lock

@@ -8,7 +8,7 @@ license = "MIT"
 [tool.poetry.dependencies]
 python = "^3.7"
 algoliasearch = ">=2.0,<3.0"
-alembic = "1.5.3"
+alembic = "1.5.8"
 bandit = "1.5.1"
 click = "7.1.2"
 flake8 = "3.9.0"