bug: fluentbit lua filter code fails to generate valid lua code

[v-davegillies-upscale]

Describe the issue

I'm attempting to use the lua filter plugin but am seeing this error:

error] [luajit] error loading buffer: [string "fluentbit.lua"]:1: 'end' expected near '<eof>'

To Reproduce

apiVersion: fluentbit.fluent.io/v1alpha2
kind: ClusterFilter
metadata:
  name: my-filter
  labels:
    fluentbit.fluent.io/enabled: "true"
spec:
  match: "*"
  filters:
    - lua:
        code: |
          function cb_print(tag, timestamp, record)
              -- Add cluster and environment metadata
              record["cluster_name"] = os.getenv("CLUSTER_NAME") or "unknown"
              record["environment"] = os.getenv("CLUSTER_ENV") or "unknown"
              record["node_name"] = os.getenv("NODE_NAME") or "unknown"

              -- Add time fields for partitioning
              local t = os.date("*t", timestamp)
              record["year"] = string.format("%04d", t.year)
              record["month"] = string.format("%02d", t.month)
              record["day"] = string.format("%02d", t.day)
              record["hour"] = string.format("%02d", t.hour)
              record["minute"] = string.format("%02d", t.min)

              return 1, timestamp, record
          end
        call: "cb_print"

Expected behavior

That it'll result in valid lua code that fluentbit can use

Your Environment

- Fluent Operator version: 3.4.2
- Container Runtime: ghcr.io/fluent/fluent-operator/fluent-bit:v3.2.10
- Operating system:
- Kernel version:

How did you install fluent operator?

No response

Additional context

No response