libobjc2: Fix building with cmake-4

mingw-w64-libobjc2/PKGBUILD

@@ -7,7 +7,7 @@ if [[ ${MSYSTEM} != CLANG* ]]; then
   conflicts=("${MINGW_PACKAGE_PREFIX}-gcc-objc")
 fi
 pkgver=2.2.1
-pkgrel=2
+pkgrel=3
 pkgdesc="Objective-C runtime library intended for use with Clang. (mingw-w64)"
 arch=('any')
 mingw_arch=('mingw64' 'ucrt64' 'clang64' 'clangarm64')
@@ -17,6 +17,7 @@ depends=("${MINGW_PACKAGE_PREFIX}-gcc-libs")
 makedepends=("${MINGW_PACKAGE_PREFIX}-cmake"
              "${MINGW_PACKAGE_PREFIX}-clang"
              "${MINGW_PACKAGE_PREFIX}-lld"
+             "${MINGW_PACKAGE_PREFIX}-robin-map"
              'git')
 source=("https://github.com/gnustep/${_realname}/archive/v${pkgver}/${_realname}-${pkgver}.tar.gz"
         # Windows: Support building with strict compatibility, backport of https://github.com/gnustep/libobjc2/commit/2466c57c59d827b0ff199aaa6748739da99f8bbb.patch
@@ -57,6 +58,7 @@ build() {
     "${MINGW_PREFIX}"/bin/cmake.exe \
       -GNinja \
       -DCMAKE_INSTALL_PREFIX="${MINGW_PREFIX}" \
+      -DCMAKE_POLICY_VERSION_MINIMUM=3.5 \
       -DCMAKE_C_COMPILER="clang" \
       -DCMAKE_CXX_COMPILER="clang++" \
       -DSTRICT_APPLE_COMPATIBILITY=ON \