tests/spec: a CSOT-rewritten maxTimeMS cannot be asserted

Every client entity is built with CSOT `timeoutMS` (OP_TIMEOUT_MS, 10 s), and
CSOT overwrites `maxTimeMS` on each command with what is left of that budget.
An expectation of `maxTimeMS: 6000` therefore meets the harness's 10000, and
no amount of engine correctness would change it. Reported unsupported rather
than failed: a FAIL is a claim about the engine, and this is a claim about the
runner.

Refused unconditionally when an expected command mentions `maxTimeMS`, not
only when the two values differ, so it can never become a pass by coincidence.
Exactly one case in the corpus asserts it -- estimatedDocumentCount.json,
"estimatedDocumentCount with maxTimeMS" -- so the whole cost of the hatch is
one case, which is why it is worth taking instead of dropping `timeoutMS`.
That option is not open anyway: `timeoutMS` is what replaced the outer race
that once turned ~190 good cases into phantom timeout FAILs.

This is the only escape hatch in the runner. Everything else is either an
honest FAIL or an enumerated unsupported feature.

159/133/195 becomes 159/132/196: one case, fail to skip, and nothing else
moves.

tests/spec/run.js

@@ -646,6 +646,21 @@ function matchEvent(expected, actual, entities, pathStr) {
     for (const [k, v] of Object.entries(body || {})) {
         switch (k) {
             case 'command':
+                // The one assertion this runner cannot make, and the only
+                // escape hatch in it. Every client entity carries CSOT
+                // `timeoutMS` (see OP_TIMEOUT_MS), and CSOT overwrites
+                // `maxTimeMS` on every command with what is left of that
+                // budget -- so the value on the wire is the harness's, not the
+                // test's. Dropping `timeoutMS` is not the alternative: it is
+                // what replaced the outer race that produced ~190 phantom
+                // timeout FAILs, and it would cost far more than one case.
+                // Refused unconditionally rather than only when the values
+                // differ, so this can never turn into a pass by coincidence.
+                if (isPlainDoc(v) && Object.prototype.hasOwnProperty.call(v, 'maxTimeMS')) {
+                    throw new Unsupported('maxTimeMS in an expected command (CSOT rewrites it)');
+                }
+                match(v, actual.ev[k], entities, `${pathStr}.${k}`, true);
+                break;
             case 'reply':
                 match(v, actual.ev[k], entities, `${pathStr}.${k}`, true);
                 break;

tests/spec/scorecard.txt

@@ -13,7 +13,7 @@
 # semantics; ignoring them makes some cases pass that a full runner would
 # fail, so treat `pass` as an upper bound until M1 wires events up.
 
-total	159 pass	133 fail	195 skip	175 files	0 errored
+total	159 pass	132 fail	196 skip	175 files	0 errored
 
 # per-file: name	pass	fail	skip
 aggregate-allowdiskuse.json	3	0	0
@@ -109,7 +109,7 @@ distinct-rawdata.json	0	1	1
 distinct.json	0	2	0
 estimatedDocumentCount-comment.json	1	1	1
 estimatedDocumentCount-rawdata.json	1	0	1
-estimatedDocumentCount.json	2	2	2
+estimatedDocumentCount.json	2	1	3
 find-allowdiskuse-serverError.json	0	0	2
 find-allowdiskuse.json	3	0	0
 find-collation.json	0	1	0
@@ -348,7 +348,7 @@ distinct.json	FAIL	Distinct with a filter	MongoServerError: no such command: 'di
 estimatedDocumentCount-comment.json	SKIP	estimatedDocumentCount with document comment	needs server >= 4.4.14
 estimatedDocumentCount-comment.json	FAIL	estimatedDocumentCount with document comment - pre 4.4.14, server error	estimatedDocumentCount: expected an error, the operation succeeded
 estimatedDocumentCount-rawdata.json	SKIP	Estimated document count with rawData option	needs server >= 8.2.0
-estimatedDocumentCount.json	FAIL	estimatedDocumentCount with maxTimeMS	events client0[0].command.maxTimeMS: expected 6000, got 10000
+estimatedDocumentCount.json	SKIP	estimatedDocumentCount with maxTimeMS	runner: maxTimeMS in an expected command (CSOT rewrites it)
 estimatedDocumentCount.json	SKIP	estimatedDocumentCount errors correctly--command error	runner: failPoint
 estimatedDocumentCount.json	SKIP	estimatedDocumentCount errors correctly--socket error	runner: failPoint
 estimatedDocumentCount.json	FAIL	estimatedDocumentCount works correctly on views	estimatedDocumentCount: expected 2, got 0