Fix .env example to only show CLOUDFLARE_CF_FETCH_ENABLED

Remove CLOUDFLARE_CF_FETCH_PATH from the example since having both
enabled=false and a custom path together doesn't make sense.

Co-Authored-By: pbacondarwin@cloudflare.com <pete@bacondarwin.com>

Author: devin-ai-integration[bot]

src/content/docs/workers/wrangler/system-environment-variables.mdx

@@ -143,7 +143,6 @@ WRANGLER_LOG=debug
 WRANGLER_LOG_PATH=../Desktop/my-logs/my-log-file.log
 WRANGLER_R2_SQL_AUTH_TOKEN=<YOUR_R2_API_TOKEN_VALUE>
 CLOUDFLARE_CF_FETCH_ENABLED=false
-CLOUDFLARE_CF_FETCH_PATH=/tmp/.cf-cache.json
 ```
 
 ## Deprecated global variables