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/feature_signet.py

@@ -51,7 +51,7 @@ class SignetBasicTest(BitcoinTestFramework):
         assert_equal(mining_info['networkhashps'], Decimal('0'))
         assert_equal(mining_info['pooledtx'], 0)
 
-        self.nodes[0].generate(1)
+        self.generate(self.nodes[0], 1)
 
         self.log.info("pregenerated signet blocks check")