"--dry-run" doesn't work properly when using category option

[ruzickap]

Hello

The new feature introduced in #369 - 'Document-level options "category"' doesn't work properly with --dry-run:

Example - let's have the following file:

• install-manual-solution-2.md

---
shell: bash
cwd: /tmp
category: solution-2
---

Installation steps for Solution 2:

```sh
echo "[1] Install command in $PWD"
```

```sh
echo "[2] Install second command"
```

```sh { "category":"delete-solution" }
echo "Delete solution"
```

```sh { "category":"delete-solution" }
echo "Delete solution - second command"
```

If I run runme run --all --skip-prompts --category solution-2 --dry-run I got only first command in markdown document "processed":

❯ runme run --all --skip-prompts --category solution-2 --dry-run
#!/opt/homebrew/bin/bash

// run in "/tmp"

set -e -o pipefail
echo "[1] Install command in $PWD"

This bug is related to #580.

Thank you for looking at it...