[Xsquash4Jira | Jira Cloud] POST requests fail with /search/jql

See Epic description

Context:

The Jira Java client has a peculiar strategy for executing Search API queries:

• It uses a GET request if the payload length is less than or equal to 500 characters
• It switches to a POST request if the payload length exceeds 500 characters

By payload, we mean the JQL query string along with its query parameters (e.g., jql, fields, expand, etc.) that form the body or query string of the request.

This behavior causes issues in Jira Cloud because:

• Large payloads (>500 characters) sent via POST to the deprecated /search/jql endpoint fail
• The migration to /search/jql requires ensuring that both GET and POST cases are handled correctly

Steps to reproduce:

• Modify the batchSize limit in the configuration file → plugin.synchronisation.jira.batchSize = 100

OR/AND

• test this jql, which contains more than 500 characters, with the simulation

key in (JPRS-1, JPRS-4, JPRS-3) and key not in (toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-55,toto-56)

You should modify the key in issue keys considering your Jira Cloud instance.