Budibase: SSRF via bare fetch() in uploadUrl during AI table generation

Budibase is an open-source low-code platform. Prior to 3.39.4, uploadUrl in packages/server/src/utilities/fileUtils.ts used a bare server-side fetch for string attachment values passed by processAttachments in packages/server/src/sdk/workspace/ai/helpers/rows.ts. A builder with the AI table-generation feature could cause an attachment value to reference an internal service or cloud metadata endpoint, and the response would be stored as an attachment without fetchWithBlacklist validation. This issue is fixed in version 3.39.4.