fix(ingest/fivetran): do not materialise upstream

[anshbansal]

• Follow up this fix(ingest/fivetran): only materialize upstream lineage #9490 to remove materialisation completely. This led to badly materialised datasets that did not have all the aspects and led to a odd state in the UI without platform instances.
• This follows the consistent practice that we have adopted of 1 ingestion source not materialising other sources entities

Checklist

• The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• Links to related issues (if applicable)
• Tests for the changes have been added/updated (if applicable)
• Docs related to the changes have been added/updated (if applicable). If a new feature has been added a Usage Guide has been added for the same.
• For any breaking change/potential downtime/deprecation/big changes an entry has been made in Updating DataHub

[github-actions]

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[asikowitz]

Clearly this materialization was done on purpose previously. Not sure why though, let's try to remember to bring this up to Harshal when he gets back