Merge bitcoin/bitcoin#21090: Default to NODE_WITNESS in nLocalServices

a806647d26 [validation] Always include merkle root in coinbase commitment (Dhruv Mehta)
189128c220 [validation] Set witness script flag with p2sh for blocks (Dhruv Mehta)
ac82b99db7 [p2p] remove redundant NODE_WITNESS checks (Dhruv Mehta)
6f8b198b82 [p2p] remove unused segwitheight=-1 option (Dhruv Mehta)
eba5b1cd64 [test] remove or move tests using `-segwitheight=-1` (Dhruv Mehta)

Pull request description:

  Builds on #21009 and makes progress on remaining items in #17862

  Removing `RewindBlockIndex()` in #21009 allows the following:

  - removal of tests using `segwitheight=-1` in `p2p_segwit.py`.
  - move `test_upgrade_after_activation()` out of `p2p_segwit.py` reducing runtime
  - in turn, that allows us to drop support for `-segwitheight=-1`, which is only supported for that test.
  - that allows us to always set `NODE_WITNESS` in our local services. The only reason we don't do that is to support `-segwitheight=-1`.
  - that in turn allows us to drop all of the `GetLocalServices() & NODE_WITNESS` checks inside `net_processing.cpp`, since our local services would always include `NODE_WITNESS`

ACKs for top commit:
  mzumsande:
    Code-Review ACK a806647d26
  laanwj:
    Code review ACK a806647d26, nice cleanup
  jnewbery:
    utACK a806647d26
  theStack:
    ACK a806647d26

Tree-SHA512: 73e1a69d1d7eca1f5c38558ec6672decd0b60b16c2ef6134df6f6af71bb159e6eea160f9bb5ab0eb6723c6632d29509811e29469d0d87abbe9b69a2890fbc73e

src/chainparams.cpp

@@ -490,11 +490,8 @@ void CRegTestParams::UpdateActivationParametersFromArgs(const ArgsManager& args)
 {
     if (args.IsArgSet("-segwitheight")) {
         int64_t height = args.GetArg("-segwitheight", consensus.SegwitHeight);
-        if (height < -1 || height >= std::numeric_limits<int>::max()) {
-            throw std::runtime_error(strprintf("Activation height %ld for segwit is out of valid range. Use -1 to disable segwit.", height));
-        } else if (height == -1) {
-            LogPrintf("Segwit disabled for testing\n");
-            height = std::numeric_limits<int>::max();
+        if (height < 0 || height >= std::numeric_limits<int>::max()) {
+            throw std::runtime_error(strprintf("Activation height %ld for segwit is out of valid range.", height));
         }
         consensus.SegwitHeight = static_cast<int>(height);
     }