Perf improvement: json, plaintext_spring, plainTextEmptyFilter

[pr-benchmarks]

Scenario	Environment	Date	Old RPS	New RPS	Change	Deviation	StDev	Dependencies
json [Fixed]	Json Minimal APIs 2- Trends Intel Linux	07/08/2024 21:47:45	948,885	958,565	1.02 % (9,680) 👍	2.16 σ	4,490.61	Changes Name Version Diff Microsoft.AspNetCore.App 9.0.0-preview.7.24355.2 -> 9.0.0-preview.7.24357.1 06533a6...ebc0c70 Microsoft.NETCore.App 9.0.0-preview.7.24352.15 -> 9.0.0-preview.7.24357.2 dotnet/runtime@1d16fd1...4e278fe Microsoft.Extensions.Caching.Abstractions.dll 9.0.0-preview.7.24355.8 (New ) n/a
plaintext_spring	Spring Plaintext 9- Frameworks Database Arm 28 Linux	07/09/2024 02:31:43	701,052	809,690	15.50 % (108,638) 👍	8.69 σ	12,495.49	Changes Name Version Diff
plainTextEmptyFilter [Fixed]	Plaintext (Empty Filters) 2- Trends Intel Linux	07/08/2024 21:39:34	3,090,619	3,153,755	2.04 % (63,136) 👍	2.56 σ	24,642.03	Changes Name Version Diff Microsoft.AspNetCore.App 9.0.0-preview.7.24355.2 -> 9.0.0-preview.7.24357.1 06533a6...ebc0c70 Microsoft.NETCore.App 9.0.0-preview.7.24352.15 -> 9.0.0-preview.7.24357.2 dotnet/runtime@1d16fd1...4e278fe Microsoft.Extensions.Caching.Abstractions.dll 9.0.0-preview.7.24355.8 (New ) n/a

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