Can't execute multiline commands

With GitHub actions, one can execute multiple commands with this multiline syntax:

```yml
run: |
command1 --option1
command2 --option2
```

Such behavior, however, doesn't seem to be respected by Cypress GH action. For instance, if I have this setup:

```yml
- uses: cypress-io/github-action@v2
with:
build: |
command1 --option1
command2 --option2
```

The actual command executed will be a combined, invalid, `command1 --option1 command2 --option2`.