fix: make array acornInjectPlugins work (fixes #8410)

[sapphi-red]

Description

fixes #8410

Type of acornInjectPlugins is (() => unknown)[] | (() => unknown) and Type of acorn.Parser.extend is

acorn.Parser.extend(
  this: typeof acorn.Parser,
  ...plugins: ((BaseParser: typeof acorn.Parser) => typeof acorn.Parser)[]
): typeof acorn.Parser

Additional context

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What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

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