fix: remove non-existent extendArray import, add changeset

extendArray was removed from the codebase in #3253 (bundle size
reduction. Revert to the spread syntax that replaced it. Add a
changeset for posthog-js and @posthog/types.
EOF
)

Author: eli-r-ph

.changeset/cookieless-web-vitals.md

@@ -0,0 +1,6 @@
+---
+'posthog-js': patch
+'@posthog/types': patch
+---
+
+Enable $web_vitals reporting when cookieless mode is enabled

packages/browser/src/extensions/web-vitals/index.ts

@@ -6,7 +6,6 @@ import { WEB_VITALS_ALLOWED_METRICS, WEB_VITALS_ENABLED_SERVER_SIDE } from '../.
 import { assignableWindow, window, location } from '../../utils/globals'
 import { maskQueryParams } from '../../utils/request-utils'
 import { PERSONAL_DATA_CAMPAIGN_PARAMS, MASKED } from '../../utils/event-utils'
-import { extendArray } from '../../utils'
 
 const logger = createLogger('[Web Vitals]')
 
@@ -148,7 +147,7 @@ export class WebVitalsAutocapture {
         const customPersonalDataProperties = this._instance.config.custom_personal_data_properties
 
         const paramsToMask = maskPersonalDataProperties
-            ? extendArray([], PERSONAL_DATA_CAMPAIGN_PARAMS, customPersonalDataProperties || [])
+            ? [...PERSONAL_DATA_CAMPAIGN_PARAMS, ...(customPersonalDataProperties || [])]
             : []
 
         return maskQueryParams(href, paramsToMask, MASKED)