fix: keep apply-setters v0.2.0 in functions map for backward compatibility

The PR bumps apply-setters to v0.2.4 in go.mod. Adding v0.2.4 to the
functions registry is required so Kptfiles referencing the new version
work with the built-in runner. v0.2.0 is kept for backward compatibility
with existing Kptfiles that already reference that version.

Also revert testdata Kptfiles back to v0.2.0 since both versions are
now supported by the functions map.

Addresses reviewer question on PR #4432

Signed-off-by: NETIZEN-11 <kumarnitesh121411@gmail.com>

Author: NETIZEN-11

internal/kptops/functions.go

@@ -19,6 +19,8 @@ import (
 )
 
 var functions map[string]framework.ResourceListProcessorFunc = map[string]framework.ResourceListProcessorFunc{
+	// v0.2.0 kept for backward compatibility with existing Kptfiles
+	"ghcr.io/kptdev/krm-functions-catalog/apply-setters:v0.2.0": applySetters,
 	"ghcr.io/kptdev/krm-functions-catalog/apply-setters:v0.2.4": applySetters,
 	"ghcr.io/kptdev/krm-functions-catalog/set-labels:v0.1.5":    setLabels,
 	"ghcr.io/kptdev/krm-functions-catalog/set-namespace:v0.4.1": setNamespace,

internal/kptops/testdata/render-with-function-config/simple-bucket/Kptfile

@@ -22,5 +22,5 @@ info:
   description: A Google Cloud Storage bucket
 pipeline:
   mutators:
-    - image: ghcr.io/kptdev/krm-functions-catalog/apply-setters:v0.2.4
+    - image: ghcr.io/kptdev/krm-functions-catalog/apply-setters:v0.2.0
       configPath: setters.yaml

internal/kptops/testdata/render-with-inline-config/simple-bucket/Kptfile

@@ -8,7 +8,7 @@ info:
   description: A Google Cloud Storage bucket
 pipeline:
   mutators:
-    - image: ghcr.io/kptdev/krm-functions-catalog/apply-setters:v0.2.4
+    - image: ghcr.io/kptdev/krm-functions-catalog/apply-setters:v0.2.0
       configMap:
         name: updated-bucket-name
         namespace: updated-namespace