DOC-5599 Remove real-time data pipeline tutorial

[aimurphy]

Moved to Astra Streaming in datastax/astra-streaming-docs#156

[plpesvc-ds]

Build successful! ✅
Pull requests with matching branch name doc-5599 included in the build:

• DOC-5599 Remove real-time data pipeline tutorial #66 (this pull request)
• DOC-5599 Move real-time data pipeline tutorial from Streaming Learning to Astra Streaming astra-streaming-docs#156

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[mendonk]

+1