fix(.github/codecov): Install deps for fips codecov

[dongcarl]

An attempt to fix https://github.com/quinn-rs/quinn/actions/runs/11562272211/job/32183071070 on main and (unreleased) 0.5.6

[dongcarl]

It seems from the CI failure that code coverage builds for Windows for aws-lc-fips-sys is more complicated than expected.

More resources:

• https://github.com/aws/aws-lc/blob/main/BUILDING.md#build-prerequisites (seems to recommend ninja, nasm, cmake, and libunwind)

@mxinden @Ralith @djc I guess a decision has to be made if full coverage for aws-lc-fips-sys is worth the build system troubles

[djc]

What goal are you trying to achieve here?

[dongcarl]

@djc Just to fix https://github.com/quinn-rs/quinn/actions/runs/11562272211/job/32183071070

[djc]

@mxinden @Ralith @djc I guess a decision has to be made if full coverage for aws-lc-fips-sys is worth the build system troubles

I think we should definitely fix it so coverage builds can succeed (I'm surprised the main CI failures don't generate any notifications for me...). I think rustls has this working so it shouldn't be too hard to fix?

https://github.com/rustls/rustls/blob/main/.github/workflows/build.yml#L51

[dongcarl]

@djc Should be good to go now. Checks are passing: https://github.com/quinn-rs/quinn/actions/runs/12588265064

I can drop the last commit (meant to be temporary just for testing) if this looks good.

[gretchenfrage]

Yeah just copying what Rustls is doing makes sense, and the second commit which makes the coverage CI run in PRs combined with the fact that CI passed for this PR seems to indicate that the change works. Thank you for working on this irksome thing!

(We must remember not to merge until the second commit is removed.)