fix(tooltip): fix potential NPE when setting option with notMerge strategy

[ktx-abhay]

• Fix [Bug] Cannot read properties of null (reading 'offsetWidth') when using notMerge #20335
• Optional chaining for tooltip offsetWidth and offsetHeight

Brief Information

This pull request is in the type of:

• bug fixing
• new feature
• others

What does this PR do?

Fixed issues

Details

Before: What was the problem?

After: How does it behave after the fixing?

Document Info

One of the following should be checked.

• This PR doesn't relate to document changes
• The document should be updated later
• The document changes have been made in apache/echarts-doc#xxx

Misc

ZRender Changes

• This PR depends on ZRender changes (ecomfe/zrender#xxx).

Related test cases or examples to use the new APIs

N.A.

Others

Merging options

• Please squash the commits into a single one when merging.

Other information

[echarts-bot]

Thanks for your contribution!
The community will review it ASAP. In the meanwhile, please checkout the coding standard and Wiki about How to make a pull request.

⚠️ MISSING DOCUMENT INFO: Please make sure one of the document options are checked in this PR's description. Search "Document Info" in the description of this PR. This should be done either by the author or the reviewers of the PR.

[github-actions]

The changes brought by this PR can be previewed at: https://echarts.apache.org/examples/editor?version=PR-20435@50b715b

[Ovilia]

We sincerely appreciate your valuable contributions! We are currently running a special promotion for users who submit a Pull Request between September 25, 2024, and December 31, 2024. Eligible participants will receive a two-year enterprise membership to Baidu Comate (Please note that in order to register Comate, you need to have a phone number in China due to local regulations), valued at 2000 RMB (approximately 285 USD).

To learn more about this product, please visit https://comate.baidu.com/. If you are interested in this offer, kindly send an email with the link to your Pull Request along with your Comate username and email address to [email protected] to claim your membership.

Thank you once again for your support!

[echarts-bot]

Congratulations! Your PR has been merged. Thanks for your contribution! 👍