fix(lint): resolve no-unused-expressions errors (#23127)

## Summary

Fixes all oxlint `no-unused-expressions` violations across the codebase
by:
- Adding an oxlint override to disable the rule for
`src/js/builtins/**`, where special syntax markers like `$getter`,
`$constructor`, etc. are intentionally used as standalone expressions
- Converting short-circuit expressions (`condition && fn()`) to proper
if statements for improved code clarity
- Wrapping intentional property access side effects (e.g.,
`this.stdio;`, `err.stack;`) with the `void` operator
- Converting ternary expressions used for control flow to if/else
statements

## Test plan

- [x] `bun lint` passes with no errors

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Bot <claude-bot@bun.sh>
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

oxlint.json

@@ -78,6 +78,12 @@
         "no-empty-file": "off",
         "no-unnecessary-await": "off"
       }
+    },
+    {
+      "files": ["src/js/builtins/**"],
+      "rules": {
+        "no-unused-expressions": "off"
+      }
     }
   ]
 }