fix: remove shorthand flag for topp option in add command

[chenrui333]

see some build failure in Homebrew/homebrew-core#171893

==> /home/linuxbrew/.linuxbrew/Cellar/k8sgpt/0.3.31/bin/k8sgpt analyze --explain --filter=Service
  panic: unable to redefine 'c' shorthand in "add" flagset: it's already used for "topp" flag
  
  goroutine 1 [running]:
  github.com/spf13/pflag.(*FlagSet).AddFlag(0xc0001c6e00, 0xc00055bae0)
  	github.com/spf13/[email protected]/flag.go:874 +0x3f5
  github.com/spf13/pflag.(*FlagSet).VarPF(0xc0001c6e00, {0x4bf0978, 0x6868708}, {0x433bbd3, 0x4}, {0x4bb9e70, 0x1}, {0x444b73e, 0xca})
  	github.com/spf13/[email protected]/flag.go:831 +0x105
  github.com/spf13/pflag.(*FlagSet).VarP(...)
  	github.com/spf13/[email protected]/flag.go:837
  github.com/spf13/pflag.(*FlagSet).Int32VarP(0x4427598?, 0x5e?, {0x433bbd3?, 0x10?}, {0x4bb9e70?, 0x3d7[51](https://github.com/Homebrew/homebrew-core/actions/runs/9115237344/job/25061178026?pr=171893#step:4:52)01?}, 0x4bb1f48?, {0x444b73e?, 0x0?})
  	github.com/spf13/[email protected]/int32.go:50 +0x45
  github.com/k8sgpt-ai/k8sgpt/cmd/auth.init.0()
  	github.com/k8sgpt-ai/k8sgpt/cmd/auth/add.go:166 +0x229
  
  Error: k8sgpt: failed
  Error: k8sgpt: failed
  An exception occurred within a child process:
    Minitest::Assertion: Expected: 1
    Actual: 2

thus removing shorthand flag for topp option

[chenrui333]

cc @k8sgpt-ai/k8sgpt-maintainers

[AlexsJones]

Thanks @chenrui333 looks good