fix(timeline): fix chart can't work when axis line is not shown

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Brief Information

This pull request is in the type of:

• bug fixing
• new feature
• others

What does this PR do?

Fix a bug that the chart can't work when the axis line is not shown.

Fixed issues

• Resolves [Bug] The timeline drag becomes invalid after checkpoint is clicked #17643

Details

Before: What was the problem?

The chart throws NPE errors.

Error: TypeError: Cannot read property 'shape' of undefined at SliderTimelineView._pointerChangeTimeline

After: How does it behave after the fixing?

See the screenshot above.

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

Please refer to the first case in test/timeline-case.html

Others

Merging options

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

Other information

[echarts-bot]

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[echarts-bot]

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