fix: Remove godebug env var initialization

[vaibhavtiwari33]

What this PR does / why we need it

GODEBUG env variable isn't used anymore and hence be removed from being set at container level.

Related issues

Fixes #3091

Testing

Don't see GODEBUG env variable in init container anymore:

Before:

Spec used:

apiVersion: numaflow.numaproj.io/v1alpha1
kind: Pipeline
metadata:
  namespace: numaflow-system
  name: simple-kafka-generator
spec:
  templates:
    vertex:
      containerTemplate:
        env:
          - name: NUMAFLOW_DEBUG
            value: "true"
          - name: RUST_LOG
            value: "debug"
  vertices:
    - name: in
      source:
        # A self data generating source
        generator:
          rpu: 1
          duration: 1s
          keyCount: 5
          value: 5
    - name: cat
      scale:
        min: 1
      udf:
        container:
          image: quay.io/numaio/numaflow-js/mapper:stable
          imagePullPolicy: IfNotPresent
    - name: out
      sink:
        kafka:
          brokers:
            - kafka-svc.kafka.svc.cluster.local:9092
          topic: my-topic
  edges:
    - from: in
      to: cat
    - from: cat
      to: out

Special notes for reviewers

Anything notable for review (risk, rollout, follow-ups).

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 79.70%. Comparing base (895ac12) to head (7d661cd).
⚠️ Report is 3 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3092      +/-   ##
==========================================
- Coverage   79.74%   79.70%   -0.04%     
==========================================
  Files         289      289              
  Lines       65028    65022       -6     
==========================================
- Hits        51854    51829      -25     
- Misses      12623    12642      +19     
  Partials      551      551              

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