Revert "[web] Switch web-render option default to auto"

[zanderso]

Reverts #23090

[flutter-dashboard]

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[zanderso]

From https://logs.chromium.org/logs/flutter/buildbucket/cr-buildbucket.appspot.com/8860631468017062608/+/steps/run_web_benchmarks_html/0/stdout?format=raw

[web_benchmarks_html] [STDOUT] Launching benchmark "text_dom_cached_layout"
[web_benchmarks_html] [STDERR] Task failed: BindingError: Cannot pass deleted object as a pointer of type ParagraphBuilder*
[web_benchmarks_html] [STDERR] BindingError: Cannot pass deleted object as a pointer of type ParagraphBuilder*
[web_benchmarks_html] [STDERR]     at BindingError.<anonymous> (https://unpkg.com/canvaskit-wasm@0.19.0/bin/canvaskit.js:159:76)
[web_benchmarks_html] [STDERR]     at new BindingError (eval at Vb (https://unpkg.com/canvaskit-wasm@0.19.0/bin/canvaskit.js:158:163), <anonymous>:4:34)
[web_benchmarks_html] [STDERR]     at X (https://unpkg.com/canvaskit-wasm@0.19.0/bin/canvaskit.js:161:250)
[web_benchmarks_html] [STDERR]     at Lc.Gc [as toWireType] (https://unpkg.com/canvaskit-wasm@0.19.0/bin/canvaskit.js:170:144)
[web_benchmarks_html] [STDERR]     at ParagraphBuilder$build [as build] (eval at $c (https://unpkg.com/canvaskit-wasm@0.19.0/bin/canvaskit.js:174:403), <anonymous>:7:28)
[web_benchmarks_html] [STDERR]     at JavaScriptObject.build$0 (http://localhost:9999/main.dart.js:50017:23)
[web_benchmarks_html] [STDERR]     at CkParagraphBuilder._buildCkParagraph$0 (http://localhost:9999/main.dart.js:36100:21)
[web_benchmarks_html] [STDERR]     at CkParagraphBuilder.build$0 (http://localhost:9999/main.dart.js:36093:39)
[web_benchmarks_html] [STDERR]     at BenchTextCachedLayout.body$1 (http://localhost:9999/main.dart.js:111672:97)
[web_benchmarks_html] [STDERR]     at http://localhost:9999/main.dart.js:112081:27