change $partition variable name to $ansible_partition (#63968)

* change $partition variable name to $ansbile_partition

* Added changelog fragment

changelogs/fragments/win_partition-var.yaml

@@ -0,0 +1,2 @@
+bugfixes:
+- win_partition - Fix invalid variable name causing a failure on checks - https://github.com/ansible/ansible/issues/62401

lib/ansible/modules/windows/win_partition.ps1

@@ -214,10 +214,10 @@ if ($ansible_partition) {
     }
     else {
 
-        if ($null -ne $gpt_type -and $gpt_styles.$gpt_type -ne $partition.GptType) {
+        if ($null -ne $gpt_type -and $gpt_styles.$gpt_type -ne $ansible_partition.GptType) {
             $module.FailJson("gpt_type is not a valid parameter for existing partitions")
         }
-        if ($null -ne $mbr_type -and $mbr_styles.$mbr_type -ne $partition.MbrType) {
+        if ($null -ne $mbr_type -and $mbr_styles.$mbr_type -ne $ansible_partition.MbrType) {
             $module.FailJson("mbr_type is not a valid parameter for existing partitions")
         }