fix(us): memory leak when getting root certificate

[DonIsaac]

What does this PR do?

Fixes a memory leak when an x509 root certificate is successfully read for an https server.

How did you verify your code works?

There are already tests for this. I just ran this command to find+fix it:

leaks -atExit -- ./build/debug/bun-debug test ./test/js/bun/http/serve-body-leak.test.ts | tee leaks.log

There's a bunch of other reported leaks that I'll address in other PRs.

[robobun]

^{Updated 6:53 PM PT - Dec 30th, 2024}

❌ @DonIsaac, your commit dd4b248 has 1 failures in #8699:

• test/js/bun/http/serve-body-leak.test.ts - timeout on 🪟 2019 x64-baseline
• test/js/bun/http/serve-body-leak.test.ts - timeout on 🪟 2019 x64

---

🧪   try this PR locally:

bunx bun-pr 16073

[Jarred-Sumner]

Either one of two things are true:

• This code causes x to be invalid memory
• There are two more memory leaks in that code edit: i'm wrong

But I do think it's worth finding out if x is still valid

[DonIsaac]

• PEM_read_bio_X509 is declared by a DECLARE_PEM_rw macro.
• That function is implemented by IMPLEMENT_PEM_read_bio. It wraps a call to PEM_ASN1_read_bio and casts the returned void pointer.
• PEM_ASN1_read_bio calls PEM_bytes_read_bio here
• PEM_bytes_read_bio passes output pointers to PEM_read_bio, and will free those pointers on error
• PEM_read_bio then allocates memory here

Thus this is a memory leak.