Update Black's target-version to py37

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### Description
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Black's `target-version` was still set to `['py27', 'py36']`. Set it to `[py37]` instead.

Also update Black and other pre-commit hooks and re-format with Black.

### Checklist
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This pull request is:

- [ ] A documentation / typographical error fix
	- Good to go, no issue or tests are needed
- [ ] A short code fix
	- please include the issue number, and create an issue if none exists, which
	  must include a complete example of the issue.  one line code fixes without an
	  issue and demonstration will not be accepted.
	- Please include: `Fixes: #<issue number>` in the commit message
	- please include tests.   one line code fixes without tests will not be accepted.
- [ ] A new feature implementation
	- please include the issue number, and create an issue if none exists, which must
	  include a complete example of how the feature would look.
	- Please include: `Fixes: #<issue number>` in the commit message
	- please include tests.

**Have a nice day!**

Closes: #7536
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/7536
Pull-request-sha: b3aedf5570d7e0ba6c354e5989835260d0591b08

Change-Id: I8be85636fd2c9449b07a8626050c8bd35bd119d5

1 files changed, 4 insertions, 4 deletions

diff --git a/test/dialect/postgresql/test_reflection.py b/test/dialect/postgresql/test_reflection.py
index 0e8a18c0f..fa04dee48 100644
--- a/test/dialect/postgresql/test_reflection.py
+++ b/test/dialect/postgresql/test_reflection.py
@@ -1698,10 +1698,10 @@ class ReflectionTest(
         eq_(
             check_constraints,
             {
-                u"cc1": u"(a > 1) AND (a < 5)",
-                u"cc2": u"(a = 1) OR ((a > 2) AND (a < 5))",
-                u"cc3": u"is_positive(a)",
-                u"cc4": u"(b)::text <> 'hi\nim a name   \nyup\n'::text",
+                "cc1": "(a > 1) AND (a < 5)",
+                "cc2": "(a = 1) OR ((a > 2) AND (a < 5))",
+                "cc3": "is_positive(a)",
+                "cc4": "(b)::text <> 'hi\nim a name   \nyup\n'::text",
             },
         )