[dlib] fix problematic public target flags

[nyoma-diamond]

Mitigates #49035 (pending a fix to davisking/dlib#3125 or merge of davisking/dlib#3126)

• Changes comply with the maintainer guide.
• SHA512s are updated for each updated download.
• The "supports" clause reflects platforms that may be fixed by this new version.
• Any fixed CI baseline entries are removed from that file.
• Any patches that are no longer applied are deleted from the port's directory.
• The version database is fixed by rerunning ./vcpkg x-add-version --all and committing the result.
• Only one version is added to each modified port's versions file.

[nyoma-diamond]

@microsoft-github-policy-service agree company="DeepForm Limited"

[nyoma-diamond]

@microsoft-github-policy-service agree company="DeepForm Limited"

[BillyONeal]

This is probably good but as I'm not 110% sure I'm going to give upstream some time to look. (I'm on vacation at the moment so I'm being more cautious than usual :) )

[nyoma-diamond]

That's valid; no need to rush it 😁 It'll be good to get more eyes on this after the new year.

One potential caveat on waiting for upstream is that even if davisking/dlib#3126 is merged, it won't become available to vcpkg until a new patch/version of dlib is published, since the port pins by version tag (unless the port is adjusted to reference a specific commit instead). As a result we may still be waiting on upstream for quite a while. Upon further thinking, since #49035 is a build error which particularly impacts vcpkg (due to the ease of switching compilers, such as by having a different target triplet from the host), I think it would be useful to have the patch present in vcpkg until dlib publishes a release with the fix anyways. Reason being: In absence of a fix, it's actually impossible to build to any non-MSVC triplet right now if the host is using MSVC (based on my understanding). This also provides the benefit of allowing consumers to pin to v20.0 without issue, in case future versions of dlib causes other bugs / incompatibilities.

[BillyONeal]

One potential caveat on waiting for upstream is that even if davisking/dlib#3126 is merged, it won't become available to vcpkg until a new patch/version of dlib is published

If upstream is happy with the edits as this seems to be mostly build system changes I think we can take the patch. Just trying to avoid "putting words in their mouth" so to speak; if they merge it themselves that means they're happy and as a result I'm happy.

Oops