assert: remove unreachable code

In lib/internal/assert/assertion_error.js, line 391 assures that
`operator` is 'deepEqual' so there is no need to check the value of
`operator` in a ternary on the next line (line 392). Remove the ternary.

PR-URL: #27786
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

lib/internal/assert/assertion_error.js

@@ -374,9 +374,9 @@ class AssertionError extends Error {
       } else {
         let res = inspectValue(actual);
         let other = inspectValue(expected);
-        const knownOperators = kReadableOperator[operator];
+        const knownOperator = kReadableOperator[operator];
         if (operator === 'notDeepEqual' && res === other) {
-          res = `${knownOperators}\n\n${res}`;
+          res = `${knownOperator}\n\n${res}`;
           if (res.length > 1024) {
             res = `${res.slice(0, 1021)}...`;
           }
@@ -389,8 +389,7 @@ class AssertionError extends Error {
             other = `${other.slice(0, 509)}...`;
           }
           if (operator === 'deepEqual') {
-            const eq = operator === 'deepEqual' ? 'deep-equal' : 'equal';
-            res = `${knownOperators}\n\n${res}\n\nshould loosely ${eq}\n\n`;
+            res = `${knownOperator}\n\n${res}\n\nshould loosely deep-equal\n\n`;
           } else {
             const newOperator = kReadableOperator[`${operator}Unequal`];
             if (newOperator) {