test: drop extra generates from wallet_signrawtransactionwithwallet

bitcoin#22550 adds assertions to validate CSV/CLTV activation and
replaces the `generate()` calls with a helper `generate_to_height()` but
bitcoin#22818 activates all forks from block 1 by default, so the
`generate_to_height()` calls have been dropped.

This leaves us with the `generate()` calls being swapped for assertions.

Author: kwvg

test/functional/wallet_signrawtransactionwithwallet.py

@@ -130,7 +130,7 @@ def test_signing_with_csv(self):
         getcontext().prec = 8
 
         # Make sure CSV is active
-        self.generate(self.nodes[0], 500)
+        assert self.nodes[0].getblockchaininfo()['softforks']['csv']['active']
 
         # Create a P2SH script with CSV
         script = CScript([1, OP_CHECKSEQUENCEVERIFY, OP_DROP, OP_TRUE])
@@ -159,11 +159,11 @@ def test_signing_with_cltv(self):
         self.nodes[0].walletpassphrase("password", 9999)
         getcontext().prec = 8
 
-        # Make sure CSV is active
-        self.generate(self.nodes[0], 1500)
+        # Make sure CLTV is active
+        assert self.nodes[0].getblockchaininfo()['softforks']['bip65']['active']
 
         # Create a P2SH script with CLTV
-        script = CScript([1000, OP_CHECKLOCKTIMEVERIFY, OP_DROP, OP_TRUE])
+        script = CScript([100, OP_CHECKLOCKTIMEVERIFY, OP_DROP, OP_TRUE])
         address = script_to_p2sh(script)
 
         # Fund that address and make the spend