Fix newly introduced python warnings in XenAPI.py

[edwintorok]

Apparently some more checks got enabled on master for python that fail on the changes done to XenAPI.py on the feature branch (but these tests didn't fail at the time the changes were made, they probably weren't active yet).

[edwintorok]

Hmm the new parallel finish fails:

/home/runner/work/_actions/coverallsapp/github-action/v1/dist/index.js:40831
                        throw new Error('Parallel webhook error:' + err + ', ' + JSON.stringify(data));
                        ^

Error: Parallel webhook error:Error: {"error":"No build matching CI build number 9747[17](https://github.com/xapi-project/xen-api/actions/runs/9747174321/job/26899347309?pr=5761#step:2:18)4321 found"}, {"error":"No build matching CI build number 9747174321 found"}
    at Request._callback (/home/runner/work/_actions/coverallsapp/github-action/v1/dist/index.js:40831:31)
    at Request.self.callback (/home/runner/work/_actions/coverallsapp/github-action/v1/dist/index.js:24734:22)
    at Request.emit (node:events:513:28)
    at Request.<anonymous> (/home/runner/work/_actions/coverallsapp/github-action/v1/dist/index.js:25703:10)
    at Request.emit (node:events:513:28)
    at IncomingMessage.<anonymous> (/home/runner/work/_actions/coverallsapp/github-action/v1/dist/index.js:25625:12)
    at Object.onceWrapper (node:events:627:28)
    at IncomingMessage.emit (node:events:525:35)
    at endReadableNT (node:internal/streams/readable:1358:12)
    at processTicksAndRejections (node:internal/process/task_queues:83:[21](https://github.com/xapi-project/xen-api/actions/runs/9747174321/job/26899347309?pr=5761#step:2:22))

I'll remove it from this PR for now.

[bernhardkaindl]

Explanation: The line to just disable the warning on self._session needed to be converted to use the block syntax for disabling, because the line was too long with the disable comment at the end of the line.