cleanup IPConfig2/Http Protocol

[phip1611]

Follow-up of #1614 by @kraxel.

• missing file in .gitignore

Checklist

• Sensible git history (for example, squash "typo" or "fix" commits). See the Rewriting History guide for help.
• Update the changelog (if necessary)

[phip1611]

I never see any output in the OVMF debugcon log file. Did this ever work? @kraxel

I've also noticed that the SNP test can't run after the HTTP test. I think we missed proper cleanup in the Http integration test to reach idempotence. This can be investigated after #1621 is merged.

[nicholasbishop]

I never see any output in the OVMF debugcon log file.

It depends on how OVMF is built: https://github.com/tianocore/edk2/blob/62390a89c5eb477594b74b5e1911d65998a8abe2/OvmfPkg/README#L90

Currently, ovmf-prebuilt uses the RELEASE build target, so there's no debug output if you run with the prebuilts: https://github.com/rust-osdev/ovmf-prebuilt/blob/main/build-edk2/Dockerfile

[phip1611]

Ready for merge