fix: use a valid short flag for blobs:get output

`-o` is already used in the base command for `--offline`, so this was being quietly ignored

This can't be considered a breaking change as it has never worked. (I just tried it to be sure.)

See tj/commander.js#2055.

src/commands/blobs/blobs.ts

@@ -33,7 +33,7 @@ export const createBlobsCommand = (program: BaseCommand) => {
     )
     .argument('<store>', 'Name of the store')
     .argument('<key>', 'Object key')
-    .option('-o, --output <path>', 'Defines the filesystem path where the blob data should be persisted')
+    .option('-O, --output <path>', 'Defines the filesystem path where the blob data should be persisted')
     .alias('blob:get')
     .hook('preAction', requiresSiteInfo)
     .action(async (storeName: string, key: string, options: OptionValues, command: BaseCommand) => {