ci: check for uncommited changes after build

[hedger]

What's new

• CI: check for changes in tracked files after build and fail if there are any

Verification

• See build result for first commit in this PR

Checklist (For Reviewer)

• [x] PR has description of feature/bug or link to Confluence/Jira task
• [x] Description contains actions to verify feature/bugfix

[github-actions[bot]]

Compiled firmware for commit 2bbed994:

• 📦 Update package
• 📥 DFU file
• ☁️ Web updater