Delete our custom GC logic

[Jarred-Sumner]

What does this PR do?

• Documentation or TypeScript types (it's okay to leave the rest blank in this case)
• Code changes

How did you verify your code works?

[robobun]

^{Updated 12:51 PM PT - Apr 13th, 2025}

❌ @Jarred-Sumner, your commit 073a87a has 4 failures in Build #14895:

• test/js/web/fetch/fetch.test.ts - 1 failing on 🍎 14 aarch64
• test/js/third_party/express/res.sendFile.test.ts - 1 failing on 🍎 13 aarch64
• test/js/third_party/express/res.sendFile.test.ts - 1 failing on 🍎 14 aarch64
• test/js/third_party/express/res.sendFile.test.ts - 1 failing on 🐧 20.04 aarch64
• test/js/third_party/express/res.sendFile.test.ts - 1 failing on 🐧 12 aarch64
• test/js/third_party/express/res.sendFile.test.ts - 1 failing on 🐧 24.04 aarch64
• test/js/third_party/express/res.sendFile.test.ts - 1 failing on 🐧 3.21 aarch64
• test/js/third_party/express/res.sendFile.test.ts - 1 failing on 🐧 22.04 aarch64
• test/internal/ban-words.test.ts - 1 failing on 🍎 13 aarch64
• test/internal/ban-words.test.ts - 1 failing on 🪟 2019 x64-baseline
• test/internal/ban-words.test.ts - 1 failing on 🪟 2019 x64
• test/internal/ban-words.test.ts - 1 failing on 🍎 13 x64
• test/internal/ban-words.test.ts - 1 failing on 🍎 14 x64
• test/internal/ban-words.test.ts - 1 failing on 🍎 14 aarch64
• test/internal/ban-words.test.ts - 1 failing on 🐧 3.21 aarch64
• test/internal/ban-words.test.ts - 1 failing on 🐧 3.21 x64
• test/internal/ban-words.test.ts - 1 failing on 🐧 3.21 x64-baseline
• test/internal/ban-words.test.ts - 1 failing on 🐧 24.04 aarch64
• test/internal/ban-words.test.ts - 1 failing on 🐧 20.04 aarch64
• test/internal/ban-words.test.ts - 1 failing on 🐧 12 aarch64
• test/internal/ban-words.test.ts - 1 failing on 🐧 22.04 aarch64
• test/internal/ban-words.test.ts - 1 failing on 🐧 12 x64-baseline
• test/internal/ban-words.test.ts - 1 failing on 🐧 24.04 x64-baseline
• test/internal/ban-words.test.ts - 1 failing on 🐧 20.04 x64-baseline
• test/internal/ban-words.test.ts - 1 failing on 🐧 22.04 x64-baseline
• test/internal/ban-words.test.ts - 1 failing on 🐧 22.04 x64
• test/internal/ban-words.test.ts - 1 failing on 🐧 24.04 x64
• test/internal/ban-words.test.ts - 1 failing on 🐧 12 x64
• test/internal/ban-words.test.ts - 1 failing on 🐧 20.04 x64
• test/cli/test/test-timeout-behavior.test.ts - 1 failing on 🍎 13 aarch64
• test/cli/test/test-timeout-behavior.test.ts - 1 failing on 🍎 14 aarch64
• test/cli/test/test-timeout-behavior.test.ts - 1 failing on 🍎 14 x64
• test/cli/test/test-timeout-behavior.test.ts - 1 failing on 🍎 13 x64

---

🧪   try this PR locally:

bunx bun-pr 18999