chore: remove unused dependencies for project cleanup

- Remove `testify` dependency
- Remove `go-spew` indirect dependency
- Remove `go-difflib` indirect dependency
- Remove `yaml.v3` indirect dependency

Signed-off-by: appleboy <appleboy.tw@gmail.com>

go.mod

@@ -5,20 +5,16 @@ go 1.24.0
 require (
 	code.gitea.io/sdk/gitea v0.20.0
 	github.com/mark3labs/mcp-go v0.13.0
-	github.com/stretchr/testify v1.9.0
 	go.uber.org/zap v1.27.0
 )
 
 require (
 	github.com/42wim/httpsig v1.2.2 // indirect
-	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/davidmz/go-pageant v1.0.2 // indirect
 	github.com/go-fed/httpsig v1.1.0 // indirect
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/hashicorp/go-version v1.7.0 // indirect
-	github.com/pmezard/go-difflib v1.0.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
 	golang.org/x/crypto v0.36.0 // indirect
 	golang.org/x/sys v0.31.0 // indirect
-	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -42,7 +42,5 @@ golang.org/x/term v0.30.0/go.mod h1:NYYFdzHoI5wRh/h5tDMdMqCqPJZEuNqVR5xJLd/n67g=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
-gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=