fix(shared): prevent prototype pollution in deep merge utilities #24317

Job	Run time
Check Permissions	7s
Build Packages	1m 5s
Formatting \| Dedupe \| Changeset	1m 1s
Integration Tests (generic, chrome)	6m 30s
Integration Tests (sessions, chrome)	3m 24s
Integration Tests (ap-flows, chrome)	2m 53s
Integration Tests (handshake, chrome)	2m 30s
Integration Tests (custom, chrome)	3m 15s
Integration Tests (sessions:staging, chrome)	3m 49s
Integration Tests (nextjs, chrome, 15)	7m 15s
Integration Tests (billing, chrome)	4m 56s
Integration Tests (nuxt, chrome)	2m 35s
Integration Tests (express, chrome)	2m 22s
Integration Tests (tanstack-react-start, chrome)	2m 35s
Integration Tests (astro, chrome)	3m 23s
Integration Tests (quickstart, chrome, 15)	3m 15s
Integration Tests (quickstart, chrome, 16)	3m 5s
Integration Tests (nextjs, chrome, 16)	7m 34s
Integration Tests (vue, chrome)	2m 35s
Integration Tests (machine, chrome)	4m 57s
Integration Tests (localhost, chrome)	3m 13s
Integration Tests (handshake:staging, chrome)	2m 21s
Integration Tests (react-router, chrome)	2m 32s
Unit Tests (**)	3m 47s
Publish with pkg-pr-new	1m 45s
Static analysis	2m 51s
	1h 25m 35s

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