Fix AWS Data Firehose environment variable

[codyborders]

Updates the environment variable to DD_OP_SOURCE_AWS_DATA_FIREHOSE_ADDRESS as what's currently in the documentation will lead to errors.

What does this PR do? What is the motivation?

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Additional notes

[codyborders]

/merge

[dd-devflow]

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2025-04-14 14:08:58 UTC ℹ️ Start processing command /merge

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2025-04-14 14:09:11 UTC ℹ️ MergeQueue: waiting for PR to be ready

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2025-04-14 14:34:23 UTC ℹ️ MergeQueue: merge request added to the queue

The expected merge time in master is approximately 18m (p90).

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2025-04-14 14:50:13 UTC ❌ MergeQueue: The checks failed on this merge request

Tests failed on this commit ee85ccf:

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