fix: ensure phrase is a string (COR-10013)

Author: amandasteinhauer

packages/common/src/utils/variables.ts

@@ -84,7 +84,9 @@ export function replaceVariables(
     keepTypeIfOnlyVariable = false,
   }: { modifier?: ((variable: unknown) => unknown) | undefined; trim?: boolean; keepTypeIfOnlyVariable?: boolean } = {}
 ): string | unknown {
-  const formattedPhrase = trim ? phrase?.trim() : phrase;
+  const stringPhrase = typeof phrase === 'string' ? phrase : String(phrase ?? '');
+
+  const formattedPhrase = trim ? stringPhrase.trim() : stringPhrase;
 
   if (!formattedPhrase) {
     return '';