[libgit2] use support expressions (#31278)

ports/libgit2/portfile.cmake

@@ -37,19 +37,10 @@ foreach(GIT2_FEATURE ${FEATURES})
     elseif(GIT2_FEATURE STREQUAL "openssl")
         set_tls_backend("OpenSSL")
     elseif(GIT2_FEATURE STREQUAL "winhttp")
-        if(NOT VCPKG_TARGET_IS_WINDOWS)
-            message(FATAL_ERROR "winhttp is not supported on non-Windows and uwp platforms")
-        endif()
         set_tls_backend("WinHTTP")
     elseif(GIT2_FEATURE STREQUAL "sectransp")
-        if(NOT VCPKG_TARGET_IS_OSX)
-            message(FATAL_ERROR "sectransp is not supported on non-Apple platforms")
-        endif()
         set_tls_backend("SecureTransport")
     elseif(GIT2_FEATURE STREQUAL "mbedtls")
-        if(VCPKG_TARGET_IS_WINDOWS)
-            message(FATAL_ERROR "mbedtls is not supported on Windows because a certificate file must be specified at compile time")
-        endif()
         set_tls_backend("mbedTLS")
     endif()
 endforeach()

ports/libgit2/vcpkg.json

@@ -1,6 +1,7 @@
 {
   "name": "libgit2",
   "version-semver": "1.4.2",
+  "port-version": 1,
   "description": "Git linkable library",
   "homepage": "https://github.com/libgit2/libgit2",
   "supports": "!uwp",
@@ -23,6 +24,7 @@
   "features": {
     "mbedtls": {
       "description": "SSL support (mbedTLS)",
+      "supports": "!windows",
       "dependencies": [
         "mbedtls"
       ]
@@ -46,18 +48,12 @@
       ]
     },
     "sectransp": {
-      "description": "SSL support (sectransp)"
+      "description": "SSL support (sectransp)",
+      "supports": "!osx"
     },
     "ssh": {
       "description": "SSH support via libssh2",
       "dependencies": [
-        {
-          "name": "libgit2",
-          "default-features": false,
-          "features": [
-            "openssl"
-          ]
-        },
         "libssh2"
       ]
     },
@@ -91,7 +87,8 @@
       ]
     },
     "winhttp": {
-      "description": "SSL support (WinHTTP)"
+      "description": "SSL support (WinHTTP)",
+      "supports": "windows & !uwp"
     }
   }
 }

versions/baseline.json

@@ -4034,7 +4034,7 @@
     },
     "libgit2": {
       "baseline": "1.4.2",
-      "port-version": 0
+      "port-version": 1
     },
     "libgme": {
       "baseline": "0.6.3",

versions/l-/libgit2.json

@@ -1,5 +1,10 @@
 {
   "versions": [
+    {
+      "git-tree": "53a1a7485857995d3b4cc5a2b6eaa22d6c6b036c",
+      "version-semver": "1.4.2",
+      "port-version": 1
+    },
     {
       "git-tree": "e036ca61d2e12b110c920cadf92f0aa4f39cac9b",
       "version-semver": "1.4.2",