changefeedccl: ensure rangefeed setting is enabled in tests

[jayshrivastava]

Previously, many tests which create rangefeeds would not explicitly set the kv.rangefeed.enabled setting to be true. These tests would still work because, by default, rangefeeds are enabled via span configs. However, it was observed that span configs are not immediately applied when range splits occur. This would cause the testing rangefeed reader to encounter errors and/or timeout on very rare occasions. See #109306 (comment) for more info.

This change updates these tests to set the kv.rangefeed.enabled cluster setting to be true, which removes the dependency on span configs.

Closes: #109306
Epic: None
Release note: None

[cockroach-teamcity]

This change is 

[jayshrivastava]

bors r=miretskiy

[craig]

Build succeeded:

• Bazel Essential CI (Cockroach)

[blathers-crl]

Encountered an error creating backports. Some common things that can go wrong:

1. The backport branch might have already existed.
2. There was a merge conflict.
3. The backport branch contained merge commits.

You might need to create your backport manually using the backport tool.

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error creating merge commit from 0ec2775 to blathers/backport-release-23.1-109506: POST https://api.github.com/repos/cockroachdb/cockroach/merges: 409 Merge conflict []

you may need to manually resolve merge conflicts with the backport tool.

Backport to branch 23.1.x failed. See errors above.

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error creating merge commit from 0ec2775 to blathers/backport-release-23.1.9-rc-109506: POST https://api.github.com/repos/cockroachdb/cockroach/merges: 409 Merge conflict []

you may need to manually resolve merge conflicts with the backport tool.

Backport to branch 23.1.9-rc failed. See errors above.

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[miretskiy]

@jayshrivastava - you need to try manual backport.