Fix get recordings spec

[Karolk99]

Acknowledging the stipulations set forth:

• [x] I hereby confirm that a Pull Request involving updates to the Software Development Kit (SDK) has been smoothly merged, currently awaits processing, or is otherwise deemed unnecessary in this context.
• [x] I also affirm that another Pull Request, specifically addressing updates to the documentation body (commonly referred to as 'docs'), has either been successfully incorporated, is in the process of review, or is considered superfluous under the prevailing circumstances.

[codecov[bot]]

Codecov Report

Merging #124 (4ca1e60) into main (6538d54) will not change coverage. The diff coverage is 100.00%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #124 +/- ## ======================================= Coverage 86.18% 86.18% ======================================= Files 54 54 Lines 992 992 ======================================= Hits 855 855 Misses 137 137 ``` | [Files](https://app.codecov.io/gh/jellyfish-dev/jellyfish/pull/124?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=jellyfish-dev) | Coverage Δ | | |---|---|---| | [lib/jellyfish\_web/controllers/recording\_json.ex](https://app.codecov.io/gh/jellyfish-dev/jellyfish/pull/124?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=jellyfish-dev#diff-bGliL2plbGx5ZmlzaF93ZWIvY29udHJvbGxlcnMvcmVjb3JkaW5nX2pzb24uZXg=) | `100.00% <100.00%> (ø)` | | ------ [Continue to review full report in Codecov by Sentry](https://app.codecov.io/gh/jellyfish-dev/jellyfish/pull/124?src=pr&el=continue&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=jellyfish-dev). > **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=jellyfish-dev) > `Δ = absolute (impact)`, `ø = not affected`, `? = missing data` > Powered by [Codecov](https://app.codecov.io/gh/jellyfish-dev/jellyfish/pull/124?src=pr&el=footer&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=jellyfish-dev). Last update [6538d54...4ca1e60](https://app.codecov.io/gh/jellyfish-dev/jellyfish/pull/124?src=pr&el=lastupdated&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=jellyfish-dev). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=jellyfish-dev).

[Karolk99]

It isn't the scope of this PR, but we should think about a way to check the returned JSON structure with generated OpenApiSpec automatically.

https://membraneframework.atlassian.net/jira/software/c/projects/RTC/boards/18/backlog?selectedIssue=RTC-419