[clang-tidy-19] Enable bugprone-return-const-ref-from-parameter

```
error: returning a constant reference parameter may cause use-after-free
when the parameter is constructed from a temporary
[bugprone-return-const-ref-from-parameter,-warnings-as-errors]
  122 |     return value;
      |            ^~~~~
```

.clang-tidy

@@ -76,7 +76,6 @@ Checks: >
   -bugprone-unchecked-optional-access,
   -readability-container-size-empty,
   -bugprone-crtp-constructor-accessibility,
-  -bugprone-return-const-ref-from-parameter,
 
 # Turn all the warnings from the checks above into errors.
 WarningsAsErrors: "*"

include/fixed_containers/optional_storage.hpp

@@ -119,7 +119,7 @@ constexpr auto& get(OptionalStorage<T>& value)
 template <typename T>
 constexpr T&& get(T&& value)
 {
-    return value;
+    return std::forward<T>(value);
 }
 
 // "Transparent" here means there will be no wrapping for simple types.