CI: Don't pin vcpkg to a specific commit and let CMake run it

Ports such as OpenSSL depend on MSYS2 packages on Windows, exhibiting a problem:
when the packages are updated older versions are removed from the repository.

As a result, CI builds fail because all downloads break despite the numerous mirrors.
This commit removes the vcpkgGitCommitId property, ensuring ports are always updated.

As for letting CMake run vcpkg: it's recommended by run-vcpkg's author.

.github/workflows/build.yml

@@ -46,9 +46,6 @@ jobs:
       - uses: lukka/get-cmake@latest
 
       - uses: lukka/run-vcpkg@v11
-        with:
-          vcpkgGitCommitId: 19af97cba8ca48474e4ad15a24ed50271a9ecdac
-          runVcpkgInstall: true
 
       - uses: lukka/[email protected]
         with: