[HUDI-8233] Remove unused codepaths after HoodieFileGroupReader migration

[the-other-tim-brown]

Change Logs

• Removes unused codepaths

Impact

• Clean up the code

Risk level (write none, low medium or high below)

None

Documentation Update

Describe any necessary documentation update if there is any new feature, config, or user-facing change. If not, put "none".

• The config description must be updated if new configs are added or the default value of the configs are changed
• Any new feature or user-facing change requires updating the Hudi website. Please create a Jira ticket, attach the ticket number here and follow the instruction to make changes to the website.

Contributor's checklist

• [x] Read through contributor's guide
• [x] Change Logs and Impact were stated clearly
• [x] Adequate tests were added if applicable
• [ ] CI passed

[hudi-bot]

CI report:

• 6309eec2802059e03fa3b6c58818c1f2fbfbf535 Azure: SUCCESS

Bot commands

@hudi-bot supports the following commands:

• @hudi-bot run azure re-run the last Azure build