Fix Maven Sha256 Checksum Issue (#22600)
### Description
<!-- Describe your changes. -->
**Changes applied to maven related signing:**
* Windows sha256 file encoded by utf8(no BOM)
* powershell script task used latest version, previous 5.1 version only
supports utf8 with BOM.
* Windows sha256 file content in format 'sha256value
*filename.extension'.
* Linux sha256 file content in format 'sha256value *filename.extension'.
**More information about powershell encoding:**
Windows powershell encoding reference: [about_Character_Encoding -
PowerShell | Microsoft
Learn](https://learn.microsoft.com/en-us/powershell/module/microsoft.powershell.core/about/about_character_encoding?view=powershell-7.4)
- for version 5.1, it only has 'UTF8 Uses UTF-8 (with BOM).'
- for version v7.1 and higher, it has:
utf8: Encodes in UTF-8 format (no BOM).
utf8BOM: Encodes in UTF-8 format with Byte Order Mark (BOM)
utf8NoBOM: Encodes in UTF-8 format without Byte Order Mark (BOM)
