chore: remove null event strategy

test/unit/utils/event.spec.ts

@@ -9,7 +9,6 @@ import {
   isEventIdValid,
   isEventMatchingFilter,
   isEventSignatureValid,
-  isNullEvent,
   isReplaceableEvent,
   serializeEvent,
 } from '../../../src/utils/event'
@@ -337,16 +336,6 @@ describe('NIP-16', () => {
   })
 })
 
-describe('isNullEvent', () => {
-  it('returns true if kind equals max safe integer', () => {
-    expect(isNullEvent({ kind: Number.MAX_SAFE_INTEGER } as any)).to.be.true
-  })
-
-  it('returns false if kind does not equal max safe integer', () => {
-    expect(isNullEvent({ kind: Number.MAX_SAFE_INTEGER - 1 } as any)).to.be.false
-  })
-})
-
 // describe('NIP-27', () => {
 //   describe('isEventMatchingFilter', () => {
 //     describe('#m filter', () => {