chore: Use .includes and .startsWith, not .indexOf (#7936)

Easier to read than the diverse collection of `=== 0` and `!== -1` and `> -1` tests.

generators/python/procedures.ts

@@ -27,7 +27,7 @@ export function procedures_defreturn(block: Block, generator: PythonGenerator) {
   for (const variable of usedVariables) {
     const varName = variable.name;
     // getVars returns parameter names, not ids, for procedure blocks
-    if (block.getVars().indexOf(varName) === -1) {
+    if (!block.getVars().includes(varName)) {
       globals.push(generator.getVariableName(varName));
     }
   }