Feature Not Supported: ALTER TABLE TRUNCATE PARTITION Not Supported

# Issue: ALTER TABLE TRUNCATE PARTITION Not Supported

## Description

MatrixOne does not support truncating individual partitions using `ALTER TABLE TRUNCATE PARTITION`. This is a standard MySQL feature for quickly removing all data from a specific partition without dropping the partition structure.

## Error Statement

```sql
ALTER TABLE test_partition_range TRUNCATE PARTITION p2021;
```

## Error Message

```
ERROR 20105 (HY000) at line 1: not supported: unsupported alter option in inplace mode: truncate partition p2021
```

## Expected Behavior

The statement should remove all data from the `p2021` partition while keeping the partition structure intact.

## Actual Behavior

MatrixOne reports that truncating partitions is not supported in inplace mode, indicating this operation is not implemented.

## Impact

- Users cannot quickly clear data from specific partitions
- Must use DELETE statements which may be slower for large partitions
- Limits partition maintenance capabilities
- Migration from MySQL may require different data management strategies

## Test Case

**Case ID**: 607
**Test File**: `test_batch_61_partition.sql`
**Test Type**: Partition - TRUNCATE PARTITION operation

## Related Information

- MatrixOne supports creating partitioned tables (RANGE, HASH, KEY)
- Other partition management operations (ADD, REORGANIZE) are also not supported
- This is part of comprehensive partition functionality testing