Bump vcpkg baseline to use a non-obsolete version of libtool

The vital commit is fd766eba2b4cf59c7123d46189be373e2cee959d, but
I'm taking the most recent version of vcpkg as the new baseline
because it might as well use the latest.

.github/workflows/ci-main.yml

@@ -221,7 +221,7 @@ jobs:
           path: |
             D:/a/wesnoth/vcpkg
             D:/a/wesnoth/wesnoth/vcpkg_installed
-          key: W003
+          key: win-cache-1_16-004
 
       - name: Add msbuild to PATH
         uses: microsoft/setup-msbuild@v1.1.3
@@ -273,7 +273,7 @@ jobs:
           path: |
             D:/a/wesnoth/vcpkg
             D:/a/wesnoth/wesnoth/vcpkg_installed
-          key: W003
+          key: win-cache-1_16-004
 
       - name: Add msbuild to PATH
         uses: microsoft/setup-msbuild@v1.1.3

vcpkg.json

@@ -2,7 +2,7 @@
   "$schema": "https://raw.githubusercontent.com/microsoft/vcpkg-tool/main/docs/vcpkg.schema.json",
   "name": "wesnoth-dependencies",
   "version": "0.0.1",
-  "builtin-baseline": "b6b5c0b9a44819b095b369f507599c79ac885ec5",
+  "builtin-baseline": "877e3dc2323a4d4c3c75e7168c22a0c4e921d4db",
   "dependencies": [
     "sdl2",
     {