chore: fix c8 dependency breakage on node <= 18

.pnpmfile.cjs

@@ -8,6 +8,19 @@ module.exports = {
       if (pkg.devDependencies && pkg.devDependencies.yargs) {
         mutateYargs(pkg.devDependencies, pkg.name, 'devDependencies', context);
       }
+
+      // C8 broke Node 18 compatibility the week of July 20th 2026. 
+      // Until we complete the upgrade, we need this workaround to enable CI
+      // to continue running.
+      //
+      // TODO: Remove this workaround after Node 22 upgrade.
+      if (pkg.dependencies && pkg.dependencies.c8) {
+        mutateC8(pkg.dependencies, pkg.name, 'dependencies', context);
+      }
+      if (pkg.devDependencies && pkg.devDependencies.c8) {
+        mutateC8(pkg.devDependencies, pkg.name, 'devDependencies', context);
+      }
+
       return pkg;
     }
   }
@@ -22,3 +35,19 @@ function mutateYargs(deps, pkgName, depType, context) {
     deps.yargs = '18.0.0';
   }
 }
+
+/**
+ * Override C8 dependency for versions of Node <=18 to enable CI to continue functioning.
+ * 
+ * Otherwise, continue to use 10+ version.
+ */
+function mutateC8(deps, pkgName, depType, context) {
+  const nodeVersion = process.version;
+  const majorVersion = parseInt(nodeVersion.replace('v', '').split('.')[0], 10);
+
+  if (majorVersion <= 18) {
+    console.log(`[pnpmfile] Node.js version is ${nodeVersion} (<= 18). Overriding c8 to ^9.1.0 in ${pkgName}`);
+    deps.c8 = '^9.1.0';
+  }
+}
+