Describe the bug
Grafana Cloud Logs is ingesting logs with a - in the label name, resulting in an error when you try to search the logs. In GC, when using Explore Logs, for example, there is a count of logs, but they aren't searchable due to the invalid character in the log labels.

To Reproduce
Steps to reproduce the behavior:

1. Ingest logs with a hyphen in the label name
2. Try to query that data
3. Error: failed to parse series labels to categorize labels: 1:622: parse error: unexpected character inside braces: '-'

Expected behavior
I would expect for Loki to reject malformed log entries and not ingest.

Environment:

• Grafana Cloud

Screenshots, Promtail config, or terminal output
failed to parse series labels to categorize labels: 1:622: parse error: unexpected character inside braces: '-'