Bump Helm support to 3.21.0 and 4.2.0 (#2588)

* chore: bump pinned helm versions

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* fix: align kubernetes module pins for helm bump

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* docs: clarify helm and k8s version pins

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* test: update helm 4 snapshot outputs

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* test: update helm 4 postrender integration fixture

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* test: update helm 4 postrender template fixture

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---------

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Co-authored-by: yxxhero <11087727+yxxhero@users.noreply.github.com>

test/e2e/template/helmfile/testdata/snapshot/chart_need/output-helm4.yaml

@@ -0,0 +1,33 @@
+Adding repo myrepo http://localhost:18080/
+"myrepo" has been added to your repositories
+
+Building dependency release=foo, chart=$WD/temp1/foo
+Hang tight while we grab the latest from your chart repositories...
+...Successfully got an update from the "myrepo" chart repository
+Update Complete. ⎈Happy Helming!⎈
+Saving 1 charts
+Downloading raw from repo http://localhost:18080/
+Deleting outdated charts
+
+Templating release=foo, chart=$WD/temp1/foo
+---
+# Source: raw/charts/dep/templates/resources.yaml
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: foo-2
+  namespace: default
+data:
+  bar: BAR
+
+
+---
+# Source: raw/templates/resources.yaml
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: foo-1
+  namespace: default
+data:
+  foo: FOO
+

test/e2e/template/helmfile/testdata/snapshot/chart_need_enable_live_output/output-helm4.yaml

@@ -0,0 +1,34 @@
+Live output is enabled
+Adding repo myrepo http://localhost:18081/
+"myrepo" has been added to your repositories
+
+Building dependency release=foo, chart=$WD/temp1/foo
+Hang tight while we grab the latest from your chart repositories...
+...Successfully got an update from the "myrepo" chart repository
+Update Complete. ⎈Happy Helming!⎈
+Saving 1 charts
+Downloading raw from repo http://localhost:18081/
+Deleting outdated charts
+
+Templating release=foo, chart=$WD/temp1/foo
+---
+# Source: raw/charts/dep/templates/resources.yaml
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: foo-2
+  namespace: default
+data:
+  bar: BAR
+
+
+---
+# Source: raw/templates/resources.yaml
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: foo-1
+  namespace: default
+data:
+  foo: FOO
+

test/e2e/template/helmfile/testdata/snapshot/oci_need/output-helm4.yaml

@@ -0,0 +1,27 @@
+Building dependency release=foo, chart=$WD/temp1/foo
+Saving 1 charts
+Downloading raw from repo oci://localhost:$REGISTRY_PORT/myrepo
+Deleting outdated charts
+
+Templating release=foo, chart=$WD/temp1/foo
+---
+# Source: raw/charts/dep/templates/resources.yaml
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: foo-2
+  namespace: default
+data:
+  bar: BAR
+
+
+---
+# Source: raw/templates/resources.yaml
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: foo-1
+  namespace: default
+data:
+  foo: FOO
+

test/e2e/template/helmfile/testdata/snapshot/postrenderer/output-helm4.yaml

@@ -13,6 +13,7 @@ data:
   two: TWO
 metadata:
   name: cm2
+
 ---
 # Source: raw/templates/resources.yaml
 apiVersion: v1
@@ -32,6 +33,7 @@ data:
   one: ONE
 metadata:
   name: cm1
+
 ---
 # Source: raw/templates/resources.yaml
 apiVersion: v1