GHA: improve vcpkg cache, add BoringSSL ECH and LibreSSL MSVC jobs

[vszakats]

• cache on a per-package basis.
  Replace manual caching with a built-in solution. It shares cached
  package builds between jobs, e.g. libssh2 only builds once
  per platform (instead of once per job). Individual packages are built
  as needed (not the whole per-job tree). It also fixes the duplicate
  cache entry issues.
  Ref: https://learn.microsoft.com/en-us/vcpkg/consume/binary-caching-github-actions-cache
  Follow-up to e26cbe2 GHA: use vcpkg to install packages for MSVC jobs #13979
  Follow-up to cb22cfc GHA: add MSVC UWP job, expand jobs with more options #14077

• add BoringSSL job with ECH enabled. The first such job in the curl CI.

• add LibreSSL job.

• use vcpkg pre-installed on the runner image, instead of rolling our
  own. This is quicker, simpler and more robust.
  Follow-up to e26cbe2 GHA: use vcpkg to install packages for MSVC jobs #13979

• show pre-installed vcpkg and ports version.

• drop gsasl dependency till it reaches the pre-installed vcpkg ports.

• re-add find . to see the binaries generated.

• simplify setting up PATH.

• exclude failing tests for any job enabling WinIDN.

• drop collecting and uploading log archives. We already dump CMake
  logs, and our build doesn't use Ninja. Rest of files weren't generated
  by the curl build. We don't aim to debug vcpkg package builds.

Closes #14090

---

TODO:

• rebase on GHA: add MSVC UWP job, expand jobs with more options #14077.
• squash into meaningful sub-commits.
• delete cache entries after merge.

[vszakats]

Hit this with LibreSSL from vcpkg. There is some confusion with also picking up a non-vcpkg OpenSSL, may be related:

libcurl-d.lib(unity_0_c.obj) : error LNK2019: unresolved external symbol sk_num referenced in function Curl_ossl_verifyhost [D:\a\curl\curl\bld\src\curl.vcxproj]
libcurl-d.lib(unity_0_c.obj) : error LNK2019: unresolved external symbol sk_value referenced in function Curl_ossl_verifyhost [D:\a\curl\curl\bld\src\curl.vcxproj]
libcurl-d.lib(unity_0_c.obj) : error LNK2019: unresolved external symbol sk_pop_free referenced in function cert_stuff [D:\a\curl\curl\bld\src\curl.vcxproj]
libcurl-d.lib(unity_0_c.obj) : error LNK2019: unresolved external symbol sk_pop referenced in function cert_stuff [D:\a\curl\curl\bld\src\curl.vcxproj]
libcurl-d.lib(unity_0_c.obj) : error LNK2019: unresolved external symbol EVP_MD_CTX_create referenced in function Curl_sha512_256it [D:\a\curl\curl\bld\src\curl.vcxproj]
libcurl-d.lib(unity_0_c.obj) : error LNK2019: unresolved external symbol EVP_MD_CTX_destroy referenced in function Curl_sha512_256it [D:\a\curl\curl\bld\src\curl.vcxproj]
libcurl-d.lib(unity_0_c.obj) : error LNK2019: unresolved external symbol SSL_CTX_add0_chain_cert referenced in function SSL_CTX_use_certificate_chain_blob [D:\a\curl\curl\bld\src\curl.vcxproj]
libcurl-d.lib(unity_0_c.obj) : error LNK2019: unresolved external symbol SSL_CTX_clear_chain_certs referenced in function SSL_CTX_use_certificate_chain_blob [D:\a\curl\curl\bld\src\curl.vcxproj]
libcurl-d.lib(unity_0_c.obj) : error LNK2019: unresolved external symbol SSL_CTX_set1_groups_list referenced in function Curl_ossl_ctx_init [D:\a\curl\curl\bld\src\curl.vcxproj]
libcurl-d.lib(unity_0_c.obj) : error LNK2019: unresolved external symbol SSL_CTX_set_min_proto_version referenced in function ossl_set_ssl_version_min_max [D:\a\curl\curl\bld\src\curl.vcxproj]
libcurl-d.lib(unity_0_c.obj) : error LNK2019: unresolved external symbol SSL_CTX_set_max_proto_version referenced in function ossl_set_ssl_version_min_max [D:\a\curl\curl\bld\src\curl.vcxproj]
D:\a\curl\curl\bld\src\curl.exe : fatal error LNK1120: 11 unresolved externals [D:\a\curl\curl\bld\src\curl.vcxproj]

Ref: https://github.com/curl/curl/actions/runs/9787764034/job/27024766559#step:6:41

[talregev]

You can have hints in the vcpkg patches.

[vszakats]

You can have hints in the vcpkg patches.

Do you have a specific place to look? (I checked the LibreSSL package, which says it's incompatible with OpenSSL, but the build phase is fine, the issue comes when trying to build against curl. Perhaps a vcpkg curl patch/wrapper?)

[talregev]

vcpkg curl patches / wrapper
one hint:
Curl should add the dependencies of the packages.