add cy login and create admin tests for https://github.com/louislam/uptime-kuma/pull/3571

[Rovel]

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Description

Add Cypress tests no new admin feature

Type of change

Please delete any options that are not relevant.

• New feature (non-breaking change which adds functionality)
• Tests

Checklist

• My code follows the style guidelines of this project
• I ran ESLint and other linters for modified files
• I have performed a self-review of my own code and tested it
• I have commented my code, particularly in hard-to-understand areas
  (including JSDoc for methods)
• My changes generate no new warnings
• My code needed automated testing. I have added them (this is optional task)

Screenshots (if any)

• Login
  

• New Admin
  

• Edit Admin