Add Promtail Deprecation Warning & Multiple Log Aggregator Warning

Update the bigbang/chart/templates/NOTES.txt to account for the following:

• Add a deprecation warning if Promtail is enabled that Promtail has been officially deprecated by Grafana and will be replaced by Alloy in Big Bang core in a future release.
  • Ensure the language/timeline is approved by Anchors
• Add a warning if 2 or more log aggregators are enabled (Promtail, Fluentbit, Alloy)
  • NOTE: Include in the logic that Alloy also need alloy-logs enabled; since Alloy provides other functionality then log aggregation