Fix export command syntax for warehouse variable

Author: ronaldbradford

src/content/docs/r2-sql/tutorials/end-to-end-pipeline.mdx

@@ -144,7 +144,7 @@ Copy the `warehouse` (ACCOUNTID_BUCKETNAME) and paste it in the `export` below.
 :::
 
 ```bash
-export $WAREHOUSE= #Paste your warehouse here
+export WAREHOUSE= #Paste your warehouse here
 ```
 
 ### (Optional) Enable compaction on your R2 Data Catalog