chore: Cleanup Fluent Bit config generation

[chrkl]

Description

Changes proposed in this pull request (what was done and why):

• Remove dead code for conditionally adding @INCLUDE statement for pipeline specific Fluent Bit sections

Changes refer to particular issues, PRs or documents:

• Improved pipeline resource cleanup #298
• fix: Clean up resources when all LogPipelines are non-reconcilable #1194

Traceability

• The PR is linked to a GitHub issue.
• The PR has a milestone set.
• The PR has a respective area and kind label.
• The follow-up issues (if any) are linked in the Related Issues section.
• If the change is user-facing, the documentation has been adjusted.
• The feature is unit-tested.
• The feature is e2e-tested.