chore(harness): bump minimum Go requirement to 1.24 and modernize (#764)

Signed-off-by: Roman Dmytrenko <rdmytrenko@gmail.com>
Co-authored-by: Sahid Velji <sahidvelji@gmail.com>

Author: erka

providers/harness/go.mod

@@ -1,8 +1,6 @@
 module github.com/open-feature/go-sdk-contrib/providers/harness
 
-go 1.23.0
-
-toolchain go1.24.4
+go 1.24.0
 
 require (
 	github.com/harness/ff-golang-server-sdk v0.1.25
@@ -15,10 +13,8 @@ require (
 	github.com/apapsch/go-jsonmerge/v2 v2.0.0 // indirect
 	github.com/cenkalti/backoff/v4 v4.2.1 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/deepmap/oapi-codegen v1.11.0 // indirect
 	github.com/deepmap/oapi-codegen/v2 v2.1.0 // indirect
 	github.com/getkin/kin-openapi v0.131.0 // indirect
-	github.com/ghodss/yaml v1.0.0 // indirect
 	github.com/go-logr/logr v1.4.3 // indirect
 	github.com/go-openapi/jsonpointer v0.21.0 // indirect
 	github.com/go-openapi/swag v0.23.0 // indirect
@@ -28,10 +24,8 @@ require (
 	github.com/hashicorp/go-cleanhttp v0.5.2 // indirect
 	github.com/hashicorp/go-retryablehttp v0.7.7 // indirect
 	github.com/hashicorp/golang-lru v1.0.2 // indirect
-	github.com/invopop/yaml v0.2.0 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
-	github.com/kr/pretty v0.3.1 // indirect
 	github.com/mailru/easyjson v0.7.7 // indirect
 	github.com/mitchellh/go-homedir v1.1.0 // indirect
 	github.com/mitchellh/mapstructure v1.3.3 // indirect
@@ -42,6 +36,7 @@ require (
 	github.com/oasdiff/yaml v0.0.0-20250309154309-f31be36b4037 // indirect
 	github.com/oasdiff/yaml3 v0.0.0-20250309153720-d2182401db90 // indirect
 	github.com/perimeterx/marshmallow v1.1.5 // indirect
+	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/spaolacci/murmur3 v1.1.0 // indirect
 	go.uber.org/atomic v1.7.0 // indirect
@@ -52,6 +47,5 @@ require (
 	golang.org/x/net v0.38.0 // indirect
 	golang.org/x/sync v0.7.0 // indirect
 	gopkg.in/cenkalti/backoff.v1 v1.1.0 // indirect
-	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )