refactor(data_structures): remove `NonNull` shim #26264

Job	Run time
Build Linter Benchmark	2m 51s
Benchmark (lexer)	1m 18s
Benchmark (parser)	2m 1s
Benchmark (transformer)	2m 0s
Benchmark (isolated_declarations)	1m 55s
Benchmark (semantic)	1m 33s
Benchmark (minifier)	2m 1s
Benchmark (codegen)	2m 15s
Benchmark linter (0)	3m 14s
Benchmark linter (1)	2m 8s
Upload benchmarks	22s
	21m 38s

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