Remove unused retry logic in proxy server

[kmcginnes]

Description

Removes the retry logic inside of the proxy server APIs.

The retry logic had a refetchMaxRetries default value of 1 and i < refetchMaxRetries. This meant only 0 is less than 1, resulting in a single execution of the for loop.

The client already has built in retries with Tanstack Query that we are dependent on. In addition, certain queries may require disabling the retry logic, which is only possible from the client. So retry logic in the server is not useful.

Validation

• Tested across multiple databases
• Tested against all three query languages

Related Issues

• Depends on Fix header forwarding in request signing in proxy server #1171

Check List

• I confirm that my contribution is made under the terms of the Apache 2.0
  license.
• I have run pnpm checks to ensure code compiles and meets standards.
• I have run pnpm test to check if all tests are passing.
• I have covered new added functionality with unit tests if necessary.
• I have added an entry in the Changelog.md.

[kmcginnes]

Marking this as draft as I have some other cleanup work to do first and this is not necessary for SPARQL query editor.