Add zap stanzas for several casks

[muneebmahmed]

Important: Do not tick a checkbox if you haven’t performed its action. Honesty is indispensable for a smooth review process.

After making all changes to a cask, verify:

• The submission is for a stable version or documented exception.
• brew audit --cask {{cask_file}} is error-free.
• brew style --fix {{cask_file}} reports no offenses.

Additionally, if adding a new cask:

• Named the cask according to the token reference.
• Checked the cask was not already refused.
• Checked the cask is submitted to the correct repo.
• brew audit --new-cask {{cask_file}} worked successfully.
• brew install --cask {{cask_file}} worked successfully.
• brew uninstall --cask {{cask_file}} worked successfully.

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Adds zap stanzas for several casks in #88469:

• amazon-workspaces
• background-music
• edex-ui
• parsec
• pennywise
• vanilla

Note that most of these casks except for vanilla don't have a desc stanza, so brew audit --cask gives a warning. I was unsure if it was necessary, since they didn't have these stanzas to begin with.