MINOR: [Website] Reword ADBC announcement

[jduo]

Reword the ADBC announcement such that Flight SQL is more clearly specified as being database-agnostic rather than vendor-specific.

[github-actions]

Thanks for opening a pull request!

Could you open an issue for this pull request on JIRA?
https://issues.apache.org/jira/browse/ARROW

Then could you also rename pull request title in the following format?

ARROW-${JIRA_ID}: [${COMPONENT}] ${SUMMARY}

See also:

• Other pull requests
• Contribution Guidelines - How to contribute patches

[lidavidm]

Could you add a notice to the top that the post was edited since its initial publication?

[lidavidm]

Suggested change

	For example, applications could use be written with [Arrow Flight SQL][flight-sql] to connect to Dremio and other databases that support the Flight SQL protocol.
	For example, applications could use [Arrow Flight SQL][flight-sql] to connect to Dremio and other databases that support the Flight SQL protocol.

(If you want, I think it's fair to link "Dremio" to the website as well.)

[lidavidm]

I think it's still fair to call them vendor-specific; after all, multiple databases also use the PostgreSQL protocol (it just doesn't have a generic name). Maybe "varies by vendor (database protocols)"?

[alamb]

Maybe a better phrase would be "Database specific protocols"

[lidavidm]

Suggested change

	But not all databases support the Flight SQL protocol. An example is Google BigQuery, which has a separate SDK that returns Arrow data. In this case, client applications that want to support additional protocols would need to integrate with each of them.
	But not all databases support Flight SQL, even if they support Arrow data. An example is Google BigQuery, which has a separate SDK that returns Arrow data. In this case, client applications that want to support additional databases would need to integrate with each of their protocols.

[alamb]

Looks good to me. Thank you @jduo

Note there are still some references to "vendor specific / agnostic" in the text such as

- **Vendor-agnostic**: ADBC drivers can implement the API using any underlying protocol, while Flight SQL requires server-side support that may not be easy to add.

If we are going to modify that language, perhaps it would be good to consistently use an alternate term (like "database-agnostic") in all places.

[alamb]

Maybe a better phrase would be "Database specific protocols"