Update dependency core-js to ^3.4.3

[renovate]

This PR contains the following updates:

Package	Type	Update	Change
core-js	dependencies	patch	^3.4.2 -> ^3.4.3

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Release Notes

zloirock/core-js

v3.4.3

Compare Source

• Fixed missed es.json.stringify and some modules from iteration helpers proposal in some entry points
• Added a workaround of String#{ endsWith, startsWith } MDN polyfills bugs, #​702
• Fixed .size property descriptor of Map / Set in the pure version
• Refactoring, some internal improvements

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