fix: explicitly prevent Qt from finding OpenSSL via empty OPENSSL_DIR

The -no-openssl flag alone didn't prevent Qt's CMake from finding and linking
the vcpkg OpenSSL library. Add OPENSSL_DIR, OPENSSL_CRYPTO_LIBRARY, and
OPENSSL_SSL_LIBRARY CMake variables set to empty strings to tell CMake not to
look for OpenSSL at all during Qt build.

This ensures Qt's network module uses only schannel (Windows native TLS), and
libtorrent is the ONLY source of OpenSSL in the final binary, eliminating
duplicate symbols that cause stack overflow in tls_parse_all_extensions.

Author: vectorrilke

.github/workflows/ci_windows_arm64_native.yaml

@@ -132,6 +132,9 @@ jobs:
             -qt-host-path "C:/Qt/${{ env.qt_version }}/msvc2022_64" `
             -system-zlib -schannel -no-openssl -qt-sqlite -sql-sqlite -no-sql-mysql -no-sql-odbc -no-sql-psql -c++std c++20 -- `
             -DCMAKE_PREFIX_PATH="$vcpkgRoot/installed/${{ env.vcpkg_triplet }}" `
+            -DOPENSSL_DIR="" `
+            -DOPENSSL_CRYPTO_LIBRARY="" `
+            -DOPENSSL_SSL_LIBRARY="" `
             -DCMAKE_TOOLCHAIN_FILE="$vcpkgRoot/scripts/buildsystems/vcpkg.cmake" `
             -DVCPKG_TARGET_TRIPLET=${{ env.vcpkg_triplet }}