[wallet-ext][explorer] disable autocapture for PostHog (MystenLabs#10428

)

## Description 

This PR disables `autocapture` because we blew through our trial event
volume, and I think we have a decent enough measure of our volume at
this point.

## Test Plan 
- Manual testing (only page views are recorded)

---
If your changes are not user-facing and not a breaking change, you can
skip the following section. Otherwise, please indicate what changed, and
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### Type of Change (Check all that apply)

- [X] user-visible impact
- [ ] breaking change for a client SDKs
- [ ] breaking change for FNs (FN binary must upgrade)
- [ ] breaking change for validators or node operators (must upgrade
binaries)
- [ ] breaking change for on-chain data layout
- [ ] necessitate either a data wipe or data migration

### Release notes
N/A

apps/core/src/PostHogAnalyticsProvider.tsx

@@ -25,6 +25,7 @@ export function PostHogAnalyticsProvider({
                 persistence: 'memory',
                 // We need to manually collect page view events since we use client-side routing
                 capture_pageview: false,
+                autocapture: false,
             }}
         >
             {children}