Cld 9542 provisioner update default database postgres version

[andrleite]

This pull request upgrades the default PostgreSQL version used throughout the project from 14.8 to 14.17. The update ensures consistency across development, CI, documentation, and infrastructure tooling.

PostgreSQL version upgrade:

• Updated the PostgreSQL Docker image version from 14.8 to 14.17 in docker-compose.yml for local development.
• Changed the PostgreSQL image in the CI workflow (.github/workflows/ci.yml) from cimg/postgres:14.8 to cimg/postgres:14.17.
• Updated the default PostgreSQL version in the Makefile from 14.8 to 14.17.
• Changed the default PostgreSQL version constant in internal/tools/aws/constants.go from 14.8 to 14.17.

Documentation update:

• Updated the migration instructions in README.md to reflect the new target version (14.17 instead of 14.8).<!-- Thank you for contributing a pull request! Here are a few tips to help you:

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Ticket Link

https://mattermost.atlassian.net/browse/CLD-9542

Release Note

 Upgrade the default PostgreSQL version used throughout the project from 14.8 to 14.17.

[mm-cloud-bot]

@andrleite: Adding the "do-not-merge/release-note-label-needed" label because no release-note block was detected, please follow our release note process to remove it.

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