chore(deps)(deps): bump flower from 2.1.0 to 2.2.0 in /backend

[dependabot]

Bumps flower from 2.1.0 to 2.2.0.

Release notes

Sourced from flower's releases.

v2.2.0

Security

• Added CSRF protection for cookie-authenticated sessions
• Added protection against cross-site state-changing requests
• Added an OAuth state check to all login handlers
• Restricted the post-login redirect to local paths
• Enabled TLS certificate validation for the RabbitMQ management API
• Escaped all table cells on the tasks and workers pages
• Escaped load average values in the workers grid
• Added HttpOnly and SameSite to session cookies
• Added the X-Content-Type-Options: nosniff header
• Limited CORS headers to the unauthenticated API
• Served API error messages as plain text

Features

• Added a logout link for OAuth sessions #1074
• Added a timeout option to the task apply API
• Added a page size selector to the tasks page #1518
• Linked task names to a list of all tasks with that name
• Linked the task counts on the workers page to the matching tasks
• Honored the column order of the tasks_columns option #1262
• Added thousands separators to task counts #1374
• Formatted durations and showed a dash for missing values
• Added search examples as placeholder text
• Made wide tables scroll sideways and shortened UUIDs on mobile
• Limited worker page task lists to 50 entries by default #1087
• Removed the Retried column from the workers page
• Named browser tabs by page

Performance and reliability

• Made persistent state saves atomic #1403
• Fixed startup failing on a corrupt persistent state database #1398
• Added a warning when state saving dominates the save interval
• Reapplied --max-tasks to restored persistent state #1380
• Honored the --purge-offline-workers grace period after worker-offline events #1190
• Inspected a worker lazily on its first page visit #1388
• Fetched worker task lists only when inspecting a single worker
• Validated the --broker-api URL at startup
• Required both --certfile and --keyfile when either is set
• Validated task API query parameters and publish payloads

Bug fixes

• Fixed worker task table column widths #1521 by @​ShubhAtWork
• Fixed the default RabbitMQ management API URL to use the management port #1232
• Fixed the theme dropdown not closing and stuck navbar tooltips
• Fixed a server error on the task page for tasks without a name

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Commits

• 4d4a9ac Set release version
• b884844 Exclude compiled and hidden files from the sdist
• fba84ef Merge remote-tracking branch 'origin/master' into 2.0
• ea34f92 Fix broken and moved links in the docs
• 1336fbd Fix the unpicklable state test on Python 3.10 to 3.13
• 0f04846 Open the state shelves with context managers
• 8034099 Apply the ruff style rewrites to the package
• b14b43d Fix the ruff errors in the tests
• b9f7189 Apply ruff's safe fixes and literal rewrites to the package
• ff33bc8 Tidy the task API test bodies and name lookups
• Additional commits viewable in compare view