[GCP] Remove lightweight module in gcp.pubsub data stream

[legoguy1000]

What does this PR do?

Remove lightweight module in gcp.pubsub data stream

Checklist

• I have reviewed tips for building integrations and this pull request is aligned with them.
• I have verified that all data streams collect metrics or logs.
• I have added an entry to my package's changelog.yml file.
• I have verified that Kibana version constraints are current according to guidelines.

Author's Checklist

• [ ]

How to test this PR locally

Related issues

• Closes [GCP] Remove lightweight module in gcp.pubsub data stream #4263

Screenshots

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Build stats

• Start Time: 2022-09-22T21:00:05.156+0000

• Duration: 19 min 11 sec

Test stats 🧪

Test	Results
Failed	0
Passed	82
Skipped	0
Total	82

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[kaiyan-sheng]

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🚀 Benchmarks report

Package gcp 👍(2) 💚(2) 💔(1)

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Data stream	Previous EPS	New EPS	Diff (%)	Result
loadbalancing_logs	3558.72	2865.33	-693.39 (-19.48%)	💔

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🌐 Coverage report

Name	Metrics % (covered/total)	Diff
Packages	100.0% (5/5)	💚
Files	100.0% (5/5)	💚 2.65
Classes	100.0% (5/5)	💚 2.65
Methods	90.816% (89/98)	👍 0.948
Lines	95.752% (1375/1436)	👍 4.424
Conditionals	100.0% (0/0)	💚