Meta: Re-bootstrap vcpkg when we update its version

Fetching package versions that were shipped after vcpkg was last
bootstrapped requires re-bootstrapping vcpkg.

Meta/ladybird.sh

@@ -127,7 +127,6 @@ build_cmake() {
 }
 
 build_vcpkg() {
-    echo "Building vcpkg"
     ( cd "$LADYBIRD_SOURCE_DIR/Toolchain" && ./BuildVcpkg.sh )
 }
 
@@ -136,10 +135,7 @@ ensure_toolchain() {
         build_cmake
     fi
 
-    # FIXME: Add a version check if needed.
-    if [ ! -x "${LADYBIRD_SOURCE_DIR}/Toolchain/Local/vcpkg/bin/vcpkg" ]; then
-        build_vcpkg
-    fi
+    build_vcpkg
 }
 
 run_gdb() {

Toolchain/BuildVcpkg.sh

@@ -26,7 +26,17 @@ PREFIX_DIR="$DIR/Local/vcpkg"
 
 mkdir -p "$DIR/Tarballs"
 pushd "$DIR/Tarballs"
-    [ ! -d vcpkg ] && git clone $GIT_REPO
+    if [[ ! -d vcpkg ]]; then
+        git clone "${GIT_REPO}"
+    else
+        bootstrapped_vcpkg_version=$(git -C vcpkg rev-parse HEAD)
+
+        if [[ "${bootstrapped_vcpkg_version}" == "${GIT_REV}" ]]; then
+            exit 0
+        fi
+    fi
+
+    echo "Building vcpkg"
 
     cd vcpkg
     git fetch origin