chore(main): release 1.8.0

[release-please]

🤖 I have created a release beep boop

1.8.0 (2024-12-09)

Features

• Add helper function for insert-or-update (#526) (6ff12ec), closes #391
• Support dml returning (#335) (7db3f37)
• Support float32 (#531) (6c3cb42)
• Support Partitioned DML (#541) (108d965), closes #496

Bug Fixes

• Add existing_nullable usage to visit_column_type (#329) (273f03b)
• Map now() to current_timestamp (#540) (4b24f33), closes #497
• Support storing columns for indices (#485) (93579c8)
• Support THEN RETURN for insert, update, delete (#503) (ac64472)

Dependencies

• Add nh3 (#481) (3c2bcf9)
• Add proto plus (#482) (8663453)
• Update all deps (#413) (25d9d2c)

Documentation

• Add sample for read-only transactions (#533) (d2d72b6)
• Add sample for stale reads (#539) (e9df810)
• Add samples for Spanner-specific features (#492) (a6ed382)
• Cleanup the transaction section of README a bit (#545) (c3b5df5)
• Fix readme typo (#487) (b452b4f)

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[release-please]

🤖 Created releases:

• v1.8.0

🌻

[release-trigger]

Triggered job: cloud-devrel/client-libraries/python/googleapis/python-spanner-sqlalchemy/release/release (2024-12-09T11:13:16.491Z)

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