scripted-diff: replace remaining Python test equality asserts

Some Python functional tests still use plain `assert x == y`.
The earlier commits convert the ambiguous assert patterns by hand, so this commit can rewrite the remaining safe cases mechanically.
The verify script excludes `wallet_bumpfee.py`, `test_framework/netutil.py`, and `test_framework/authproxy.py`, which still contain assert forms that the plain line-based substitution would misidentify.

-BEGIN VERIFY SCRIPT-
perl -pi -e 's/^(\s*)assert (.+?) == ([^,#]+?)$/\1assert_equal(\2, \3)/' $(git ls-files -- 'test/functional' \
':(exclude)test/functional/wallet_bumpfee.py' ':(exclude)test/functional/test_framework/netutil.py' ':(exclude)test/functional/test_framework/authproxy.py')
-END VERIFY SCRIPT-

test/functional/p2p_headers_sync_with_minchainwork.py

@@ -68,7 +68,7 @@ class RejectLowDifficultyHeadersTest(BitcoinTestFramework):
 
         def check_node3_chaintips(num_tips, tip_hash, height):
             node3_chaintips = self.nodes[3].getchaintips()
-            assert len(node3_chaintips) == num_tips
+            assert_equal(len(node3_chaintips), num_tips)
             assert {
                 'height': height,
                 'hash': tip_hash,
@@ -80,7 +80,7 @@ class RejectLowDifficultyHeadersTest(BitcoinTestFramework):
 
         for node in self.nodes[1:3]:
             chaintips = node.getchaintips()
-            assert len(chaintips) == 1
+            assert_equal(len(chaintips), 1)
             assert {
                 'height': 0,
                 'hash': '0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206',
@@ -103,7 +103,7 @@ class RejectLowDifficultyHeadersTest(BitcoinTestFramework):
             'status': 'active',
         } in self.nodes[2].getchaintips()
 
-        assert len(self.nodes[2].getchaintips()) == 1
+        assert_equal(len(self.nodes[2].getchaintips()), 1)
 
         self.log.info("Check that node3 accepted these headers as well")
         check_node3_chaintips(2, self.nodes[0].getbestblockhash(), NODE1_BLOCKS_REQUIRED)