Trail slash in $ref

We get an error when we work with:
```
$ref: "./common.yaml/#/components/schemas/ErrorResponse"
```
it should work as:
```
$ref: "./common.yaml#/components/schemas/ErrorResponse"
```

And we get now

```
 Error opening file "**/**/**/**/openapi/travel-rule/common.yaml/"
```

The document is a validated by the openapi.

P.S: Can't change the openapi its a 3º party.