fix(github-cli): replace template literal with single quotes (eslint mutation)

The local build's eslint --fix step rewrote a no-interpolation
template literal to single quotes; CI's 'Fail build on mutation'
guard caught that the mutation wasn't committed. Apply the fix.

Author: isadeks

cli/src/commands/github.ts

@@ -74,7 +74,7 @@ export function makeGithubCommand(): Command {
         console.log('receiver can verify the HMAC:');
         console.log();
         if (webhookSecretArn) {
-          console.log(`  bgagent github set-webhook-secret    # interactive prompt`);
+          console.log('  bgagent github set-webhook-secret    # interactive prompt');
           console.log();
           console.log(`  Secret ARN: ${webhookSecretArn}`);
         } else {