Adds Orion database URL to block auto-registration memoization key

[desertaxle]

Adds PREFECT_ORION_DATABASE_CONNECTION_URL to block auto-registration memoization key to ensure that block auto-registration happens each time the backing database is changed.

Closes #7347

Example

# From fresh install, start Orion server
prefect orion start

# View blocks in UI 👀 

# Stop Orion server and start Postgres instance
docker run -d --name orion_postgres -v oriondb:/var/lib/postgresql/data -p 5432:5432 -e POSTGRES_USER=postgres -e POSTGRES_PASSWORD=yourTopSecretPassword -e POSTGRES_DB=orion postgres:latest

# Set Orion DB URL
export PREFECT_ORION_DATABASE_CONNECTION_URL="postgresql+asyncpg://postgres:yourTopSecretPassword@localhost:5432/orion"

# Start Orion server
prefect orion start

# Confirm blocks in UI 👀 

Checklist

• This pull request references any related issue by including "closes <link to issue>"
  • If no issue exists and your change is not a small fix, please create an issue first.
• This pull request includes tests or only affects documentation.
• This pull request includes a label categorizing the change e.g. fix, feature, enhancement

[netlify]

✅ Deploy Preview for prefect-orion ready!

Name	Link
🔨 Latest commit	0c69705
🔍 Latest deploy log	https://app.netlify.com/sites/prefect-orion/deploys/635aa48f1344c90008cccfcf
😎 Deploy Preview	https://deploy-preview-7350--prefect-orion.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify site settings.