Revert "compat(http2) validations and some behavior fixes (#19558)"

[190n]

What does this PR do?

This reverts PR #19558. It makes test-http2-client-upload.js fail in debug and flaky in release:

Mismatched noop function calls. Expected exactly 1, actual 0.
    at <anonymous> (/Users/ben/code/bun/workers/test/js/node/test/parallel/test-http2-client-upload.js:48:31)
    at onceWrapper (unknown)
    at emit (node:events:139:22)
    at emitListeningNextTick (node:net:1338:13)

How did you verify your code works?

The test passes with the commit reverted

[robobun]

^{Updated 5:52 PM PT - May 12th, 2025}

❌ @190n, your commit f7b75cf has 1 failures in Build #16536:

• test/js/third_party/@duckdb/node-api/duckdb.test.ts - segmentation fault on 🐧 20.04 x64

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🧪   To try this PR locally:

bunx bun-pr 19616

That installs a local version of the PR into your bun-19616 executable, so you can run:

bun-19616 --bun