fix(otlp): remove extra double-quote in env var (#14837)

The env var code won't work as written due to the typo'd duplicated
double-quote.

## IS YOUR CHANGE URGENT?  

Help us prioritize incoming PRs by letting us know when the change needs
to go live.
- [ ] Urgent deadline (GA date, etc.): <!-- ENTER DATE HERE -->
- [ ] Other deadline: <!-- ENTER DATE HERE -->
- [x] None: Not urgent, can wait up to 1 week+

## PRE-MERGE CHECKLIST

*Make sure you've checked the following before merging your changes:*

- [ ] Checked Vercel preview for correctness, including links
- [ ] PR was reviewed and approved by any necessary SMEs (subject matter
experts)
- [ ] PR was reviewed and approved by a member of the [Sentry docs
team](https://github.com/orgs/getsentry/teams/docs)

Author: mjq

docs/concepts/otlp/index.mdx

@@ -17,7 +17,7 @@ Sentry can ingest [OpenTelemetry](https://opentelemetry.io) traces directly via
 The easiest way to configure an OpenTelemetry exporter is with environment variables. You'll need to configure the trace endpoint URL, as well as the authentication headers. Set these variables on the server where your application is running.
 
 ```bash {filename: .env}
-export OTEL_EXPORTER_OTLP_TRACES_ENDPOINT="___OTLP_TRACES_URL___""
+export OTEL_EXPORTER_OTLP_TRACES_ENDPOINT="___OTLP_TRACES_URL___"
 export OTEL_EXPORTER_OTLP_TRACES_HEADERS="x-sentry-auth=sentry sentry_key=___PUBLIC_KEY___"
 ```