Fix INP durationThreshold bug when set to 0 (#372)

When INP's `durationThreshold` was set to a value of `0`, it would actually
ignore all values under 40 ms because the logical (||) operator was used.

Use nullish coalescing operator instead to fix this bug.

src/onINP.ts

@@ -206,7 +206,7 @@ export const onINP = (onReport: INPReportCallback, opts?: ReportOpts) => {
       // and performance. Running this callback for any interaction that spans
       // just one or two frames is likely not worth the insight that could be
       // gained.
-      durationThreshold: opts!.durationThreshold || 40,
+      durationThreshold: opts!.durationThreshold ?? 40,
     } as PerformanceObserverInit);
 
     report = bindReporter(