[3.13] Gateway release checklist

[lena-larionova]

Before release:

• Generate API specs
• Public keys
• Release version matrix
• SBOM link
• Generate kong.conf
• Generate PDK
• Generate CLI
• Generate latest plugin updates
• Make release branch PR
• Generate changelog
• Bump release version
• Breaking changes and deprecations

Release day:

• Merge all outstanding docs
• Merge release PR

After release:

• Reindex algolia
• Reindex Kapa sources

See release checklist doc for instructions for each thing.