[CI] Deduplicate and clean XML test reports (#12332)

This PR does the following:
- When running on a shard,  removes the tests that will not run on the current shard from the suite. We'll no longer get the message `Test running on shard X of Y` in the XML reports. This will result in cleaner test reports.
- Adds the shard index or `no-shard` to the generated XML report file name. Currently, the reports generated when sharding is present are overwritten in S3 by the last shard to finish in the CI pipeline. This change is needed as part of #11670.
- Since the same tests might run on different configurations (CPU, GPU), it uploads the result of each configuration in a subdirectory in S3 (e.g `/pytest-results/frontend_aarch64`).