static_cast<int> for QByteArray::size with std::max

QByteArray::size returns qsizetype in Qt6, which needs to be
converted to an int to pass to std::max.

src/util/cache.cpp

@@ -16,7 +16,7 @@ cache_key_t cacheKeyFromMessageDigest(const QByteArray& messageDigest) {
     // 5 Hash function Usage
     // 5.1 Truncated Message Digest
     const auto significantByteCount = math_min(
-            messageDigest.size(),
+            static_cast<int>(messageDigest.size()),
             static_cast<int>(sizeof(cache_key_t)));
     for (auto i = 0; i < significantByteCount; ++i) {
         // Only 8 bits are relevant and we don't want the sign