fix: fix dynamodb drop table

[LuQQiu]

First PR of https://github.com/lancedb/lancedb/issues/1812

Add the delete function to external manifest to delete manifest related metadata during drop_table

[github-actions[bot]]

ACTION NEEDED Lance follows the Conventional Commits specification for release automation.

The PR title and description are used as the merge commit message. Please update your PR title and description to match the specification.

For details on the error please inspect the "PR Title Check" action.

[LuQQiu]

Second PR: https://github.com/lancedb/lancedb/pull/1866 which wait for lance release

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 63.41463% with 15 lines in your changes missing coverage. Please review.

Project coverage is 77.89%. Comparing base (920b191) to head (fa0e45d). Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...ust/lance-table/src/io/commit/external_manifest.rs	0.00%	8 Missing :warning:
rust/lance-table/src/io/commit/dynamodb.rs	85.18%	2 Missing and 2 partials :warning:
rust/lance-table/src/io/commit.rs	0.00%	3 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #3152 +/- ## ========================================== + Coverage 77.87% 77.89% +0.01% ========================================== Files 242 242 Lines 82214 82368 +154 Branches 82214 82368 +154 ========================================== + Hits 64028 64157 +129 - Misses 14987 15004 +17 - Partials 3199 3207 +8 ``` | [Flag](https://app.codecov.io/gh/lancedb/lance/pull/3152/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=lancedb) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/lancedb/lance/pull/3152/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=lancedb) | `77.89% <63.41%> (+0.01%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=lancedb#carryforward-flags-in-the-pull-request-comment) to find out more.

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