build: fix PR coverage comment formatting

PR-URL: #12346
Reviewed-by: Athan Reines <kgryte@gmail.com>

Author: anandkaranubc

.github/workflows/publish_coverage_pr.yml

@@ -88,7 +88,7 @@ jobs:
             const fs = require( 'fs' );
 
             const prNumber = parseInt( process.env.PR_NUMBER, 10 );
-            const report = fs.readFileSync( 'pr-metadata/report', 'utf8' );
+            const report = fs.readFileSync( 'pr-metadata/report', 'utf8' ).replace( /\\n/g, '\n' );
 
             const { data: comments } = await github.rest.issues.listComments({
               'issue_number': prNumber,