fix(ast/estree): Add custom serializer for extends field of TSInterfaceDeclaration

[therewillbecode]

Make theextends field in TSInterfaceDeclaration serialize to [] instead of null for interface declarations when the field is empty.

"extends": null -> "extends": []

PR is part of ongoing work to align our AST's ESTree output with that of TS-ESLint's. Relates to #9705

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[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #9996 will not alter performance

_{Comparing therewillbecode:fix/interface-extends (282030a) with main (9df65b7)}

Summary

✅ 33 untouched benchmarks