refactor(common): implement same empty values check for the library solidity

Author: isaacdecoded

library-solidity/tasks/utils/loadVariables.ts

@@ -1,8 +1,11 @@
-// Get the required environment variable, throw an error if it's not set
-// We only check if the variable is set, not if it's empty
+// Get the required environment variable, throw an error if it's not set or empty
 export function getRequiredEnvVar(name: string): string {
   if (!(name in process.env)) {
     throw new Error(`"${name}" env variable is not set`);
   }
-  return process.env[name]!;
+  const value = process.env[name]!;
+  if (value.trim() === '') {
+    throw new Error(`"${name}" env variable is set but empty`);
+  }
+  return value;
 }