fix(operator): Use correct field name for remote write client timeout

[periklis]

What this PR does / why we need it:
Since Loki switched to vendor the Prometheus RemoteWriteConfig struct for it's remote write client config, the Operator is missing to use the correct field name for the client timeout. This PR fixes the missing rename for the timeout field from timeout to remote_timeout.

Which issue(s) this PR fixes:
Fixes #11731

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• CHANGELOG.md updated
  • If the change is worth mentioning in the release notes, add add-to-release-notes label
• Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• For Helm chart changes bump the Helm chart version in production/helm/loki/Chart.yaml and update production/helm/loki/CHANGELOG.md and production/helm/loki/README.md. Example PR
• If the change is deprecating or removing a configuration option, update the deprecated-config.yaml and deleted-config.yaml files respectively in the tools/deprecated-config-checker directory. Example PR

[JoaoBraveCoding]

lgtm

[xperimental]

Looks good to me, just needs to be updated to get around the conflict.