scripted-diff: Use generate* from TestFramework

-BEGIN VERIFY SCRIPT-
 sed --regexp-extended -i \
     's/((self\.)?(nodes\[[^]]+\]|[a-z_]*(wallet|node)[0-9a-z_]*))\.(generate(|toaddress|block|todescriptor)(\(|, ))/self.\5\1, /g' \
     $(git grep -l generate ./test | grep -v 'test_framework/' | grep -v 'feature_rbf')
-END VERIFY SCRIPT-

test/functional/wallet_signer.py

@@ -108,7 +108,7 @@ class WalletSignerTest(BitcoinTestFramework):
 
         self.log.info('Prepare mock PSBT')
         self.nodes[0].sendtoaddress(address1, 1)
-        self.nodes[0].generate(1)
+        self.generate(self.nodes[0], 1)
         self.sync_all()
 
         # Load private key into wallet to generate a signed PSBT for the mock