build: use latest version of Formpack to add big-image support DEV-1172

[rajpatel24]

🗒️ Checklist

1. run linter locally
2. update developer docs (API, README, inline, etc.), if any
3. for user-facing doc changes create a Zulip thread at #Support Docs Updates, if any
4. draft PR with a title <type>(<scope>)<!>: <title> DEV-1234
5. assign yourself, tag PR: at least Front end and/or Back end or workflow
6. fill in the template below and delete template comments
7. review thyself: read the diff and repro the preview as written
8. open PR & confirm that CI passes & request reviewers, if needed
9. delete this section before merging

📣 Summary

Update KPI to use the latest Formpack release, which adds support for big-image as a valid media type in export workflow.

📖 Description

This PR updates the formpack dependency hash in requirements.in, requirements.txt, and dev_requirements.txt to use the commit from formpack#336. That PR introduces support for big-image as a valid media type to prevent translation mismatches in exports.

Please see the linear comment for more details.

👀 Preview steps

1. ℹ️ Download the form: test_form.xlsx
2. Deploy the form and submit at least one response.
3. 🔴 [on release] try exporting the data, it fails with TranslationError: Mismatched labels and translations: [label] [None, big-image] 1!=2.
4. 🟢 [on PR] try exporting the data, the export should complete successfully.

[noliveleger]

@rajpatel24 let's merge formpack first and then use the commit of the merge id in KPI.
You should change your title. It's not a fix. I would use "build: use latest version of formpack to add big-image support" .
What do you think?