fix: revert change default read_consistency_interval=5s (#2327)

This reverts commit a547c523c2 or #2281

The current implementation can cause panics and performance degradation.
I will bring this back with more testing in
https://github.com/lancedb/lancedb/pull/2311

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **Documentation**
- Enhanced clarity on read consistency settings with updated
descriptions and default behavior.
- Removed outdated warnings about eventual consistency from the
troubleshooting guide.

- **Refactor**
- Streamlined the handling of the read consistency interval across
integrations, now defaulting to "None" for improved performance.
  - Simplified internal logic to offer a more consistent experience.

- **Tests**
- Updated test expectations to reflect the new default representation
for the read consistency interval.
- Removed redundant tests related to "no consistency" settings for
streamlined testing.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

python/python/tests/docs/test_guide_tables.py

@@ -315,11 +315,6 @@ def test_table():
     db = lancedb.connect(uri, read_consistency_interval=timedelta(seconds=5))
     tbl = db.open_table("test_table")
     # --8<-- [end:table_eventual_consistency]
-    # --8<-- [start:table_no_consistency]
-    uri = "data/sample-lancedb"
-    db = lancedb.connect(uri, read_consistency_interval=None)
-    tbl = db.open_table("test_table")
-    # --8<-- [end:table_no_consistency]
     # --8<-- [start:table_checkout_latest]
     tbl = db.open_table("test_table")
 
@@ -574,12 +569,6 @@ async def test_table_async():
     )
     async_tbl = await async_db.open_table("test_table_async")
     # --8<-- [end:table_async_eventual_consistency]
-    # --8<-- [start:table_async_no_consistency]
-    uri = "data/sample-lancedb"
-    async_db = await lancedb.connect_async(uri, read_consistency_interval=None)
-    async_tbl = await async_db.open_table("test_table_async")
-    # --8<-- [end:table_async_no_consistency]
-
     # --8<-- [start:table_async_checkout_latest]
     async_tbl = await async_db.open_table("test_table_async")