backports/cura: fix build

backports/cura/APKBUILD

@@ -4,7 +4,7 @@ pkgname=cura
 # uranium and curaengine packages must be updated in sync with this verion number
 # py3-pynest2d and fdm-materials should be checked as well, but their versions are not always in sync
 pkgver=5.2.2
-pkgrel=0
+pkgrel=1
 pkgdesc="3D printer / slicing GUI built on top of the Uranium framework"
 url="https://ultimaker.com/software/ultimaker-cura"
 arch="noarch !ppc64le !x86 !armhf !riscv64 !s390x !armv7" # ppc64le: no py3-keyring
@@ -42,8 +42,10 @@ builddir="$srcdir/Cura-$pkgver"
 options="!check" # tests broken after v5.x
 
 build() {
+	local pyver="$(python3 -c 'import sys; print(f"{sys.version_info.major}.{sys.version_info.minor}")')"
 	cmake -B build -G Ninja \
 		-DCURA_VERSION=$pkgver \
+		-DPython_VERSION=$pyver \
 		-DURANIUM_DIR=/usr/share/uranium \
 		-DCMAKE_INSTALL_PREFIX=/usr \
 		-DCMAKE_INSTALL_LIBDIR=lib \