fix(helm): add missing global.extraArgs to read deployment

[lukasstockner]

What this PR does / why we need it:
The read Deployment currently does not respect .Values.global.extraArgs, it is only applied in the StatefulSet.
Therefore, this PR adds it to the Deployment as well.

Which issue(s) this PR fixes:
Unreported.

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• Title matches the required conventional commits format, see here
  • Note that Promtail is considered to be feature complete, and future development for logs collection will be in Grafana Alloy. As such, feat PRs are unlikely to be accepted unless a case can be made for the feature actually being a bug fix to existing behavior.
• Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• 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