refactor: remove unnesessary escape.

rules/windows/powershell/powershell_script/posh_ps_invoke_obfuscation_stdin.yml

@@ -6,7 +6,7 @@ references:
     - https://github.com/Neo23x0/sigma/issues/1009  #(Task 25)
 author: Jonathan Cheong, oscd.community
 date: 2020/10/15
-modified: 2022/11/29
+modified: 2022/12/03
 tags:
     - attack.defense_evasion
     - attack.t1027
@@ -18,7 +18,7 @@ logsource:
     definition: Script block logging must be enabled
 detection:
     selection_4104:
-        ScriptBlockText|re: '.*cmd.{0,5}(?:\/c|\/r).+powershell.+(?:\$?\{?input\}?|noexit).+\"'
+        ScriptBlockText|re: '.*cmd.{0,5}(?:/c|/r).+powershell.+(?:\$?\{?input\}?|noexit).+"'
     condition: selection_4104
 falsepositives:
     - Unknown