coin: Update vcpkg to 2026.06.01-qt

This switches vcpkg back to a specific tag of the master branch of our
fork. That's why we can remove the "reference" key from the
configuration too, since master is the default branch.

The updated protobuf port only builds the libprotoc compiler library
when the target triplet equals the host triplet, or when the libprotoc
or target-protoc feature is requested. Since we always build against
our custom *-qt triplets, which never match the host triplet, request
the libprotoc feature so that protobuf::libprotoc is available and
qtgrpc can build qtprotobufgen.

Pick-to: 6.12
Change-Id: Ief4b12c57c082f94b2bcfae6fd02ebac7018a5c9
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

coin/provisioning/common/shared/vcpkg/vcpkg-configuration.json

@@ -3,8 +3,7 @@
   "default-registry": {
     "kind": "git",
     "repository": "https://git.qt.io/qtbuildsystem/vcpkg",
-    "reference": "refs/tags/2026.05.05-ohos",
-    "baseline": "e59d4f2aeeb7f21a7d22b078111223ef71a509f2"
+    "baseline": "93580fc29654eec8d22804a01d7191284d65f28e"
   },
   "overlay-triplets": [ "./../triplets" ]
 }

coin/provisioning/common/shared/vcpkg/vcpkg.json

@@ -13,7 +13,8 @@
     },
     {
       "name": "protobuf",
-      "platform": "!osx & !ohos"
+      "platform": "!osx & !ohos",
+      "features": [ "libprotoc" ]
     },
     {
       "name": "protobuf",

coin/provisioning/common/shared/vcpkg_version.txt

@@ -1 +1 @@
-vcpkg_version=2026.05.05-ohos
+vcpkg_version=2026.06.01-qt