refactor(ini): simplify `stringify()` #16818

Job	Run time
test-node (latest, ubuntu-latest)	11s
test (v1.x, ubuntu-latest)	2m 19s
test (v1.x, windows-latest)	2m 49s
wasm (crypto/_wasm)	5s
lint (ubuntu-latest)	26s
test (v1.x, macOS-latest)	2m 13s
lint (windows-latest)	36s
test (v2.x, ubuntu-latest)	4m 56s
test (v2.x, windows-latest)	5m 10s
test (v2.x, macOS-latest)	5m 16s
test (canary, ubuntu-latest)	5m 31s
test (canary, windows-latest)	6m 10s
test (canary, macOS-latest)	4m 16s
	39m 58s

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