lambda-promtail regex fails for vpc flow logs with hourly partition

[declan-fitzpatrick]

Describe the bug
When AWS VPC Flow logs are partitioned by every hour, rather than the default 24 hours, it adds an 'hour' folder

If you enable hourly partitions, the files are delivered to the following location.
bucket-and-optional-prefix/AWSLogs/account_id/vpcflowlogs/region/year/month/day/hour/

and this causes the regex to fail, and result in {"errorMessage":"type of S3 event could not be determined for object ...

To Reproduce
Steps to reproduce the behavior:

1. Deploy lambda-promtail,
   1. Create S3 bucket,
   2. Create VPC flow log, with hourly partitioning:

resource "aws_flow_log" "example" {
  log_destination      = aws_s3_bucket.example.arn
  log_destination_type = "s3"
  traffic_type         = "ALL"
  vpc_id               = aws_vpc.example.id
  destination_options {
    file_format        = "parquet"
    per_hour_partition = true
  }
}

3. Observe lambda-promtail logs

Expected behavior
Either:

• update docs to highlight unsupported hourly partition
• update regex

Environment:

• Infrastructure: AWS Lambda
• Deployment tool: Terraform