chore(main): release Postal.AspNetCore 3.1.0

[github-actions[bot]]

:robot: I have created a release beep boop

3.1.0 (2023-09-14)

Features

• update dependency (4e23072)
• use endpoint routing (c4d6e98)

Bug Fixes

• cicd (1f7a908)
• Headers are read-only, response has already started (d8ff521)
• null check (6ff20eb)
• remove tools directory (3e69864)
• test case (1d44737)

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[github-actions[bot]]

:robot: Release is at https://github.com/hermanho/postal.aspnetcore/releases/tag/Postal.AspNetCore-v3.1.0 :sunflower: