Removed mandatory type attribute for Meta op, which is redundant with Meta op impl registry

src/backend/OperatorImpl.cpp

@@ -74,13 +74,6 @@ Aidge::ImplSpec Aidge::OperatorImpl::getRequiredSpec() const {
 
         requiredSpec.outputs.push_back({opTensor.getOutput(i)->dataType(), opTensor.getOutput(i)->dataFormat(), dims});
     }
-    // Attributes
-    if (!mOp.isAtomic()) {
-        requiredSpec.attrs.setAttr("type:!", mOp.type()); // :! mandatory qualifier
-    }
-    else {
-        requiredSpec.attrs.setAttr("type", mOp.type());
-    }
 
     const auto& inhAttrs = mOp.inheritedAttributes();
     if (inhAttrs) {