Blockchain: get height of RingCT fork programmatically

Get height of the RingCT fork to start the output distributuon programmatically, instead of using a hardcoded index.

If using a hardcoded index, when the hardfork tables are modified, this can cause segmentation faults or horrific privacy issues: https://codeberg.org/wownero/wownero/issues/488#issuecomment-2514880.

src/cryptonote_core/blockchain.cpp

@@ -2363,17 +2363,8 @@ void Blockchain::get_output_key_mask_unlocked(const uint64_t& amount, const uint
 bool Blockchain::get_output_distribution(uint64_t amount, uint64_t from_height, uint64_t to_height, uint64_t &start_height, std::vector<uint64_t> &distribution, uint64_t &base) const
 {
   // rct outputs don't exist before v4
-  if (amount == 0)
-  {
-    switch (m_nettype)
-    {
-      case STAGENET: start_height = stagenet_hard_forks[3].height; break;
-      case TESTNET: start_height = testnet_hard_forks[3].height; break;
-      case MAINNET: start_height = mainnet_hard_forks[3].height; break;
-      case FAKECHAIN: start_height = 0; break;
-      default: return false;
-    }
-  }
+  if (amount == 0 && m_nettype != network_type::FAKECHAIN)
+    start_height = m_hardfork->get_earliest_ideal_height_for_version(HF_VERSION_DYNAMIC_FEE);
   else
     start_height = 0;
   base = 0;