fix: use the same target for optimized dependencies and source files

[haoqunjiang]

fixes #4897

Description

It's the same as in

vite/packages/vite/src/node/plugins/esbuild.ts

Line 230 in 5d2c50a

target: target || undefined,

As the default target is modules, optimizing dependencies no longer introduces the unicode export syntax, therefore the bug can be circumvented.

Additional context

I would love to add tests but I haven't figured out how to set up a minimal reproduction in vite 😂

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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