Set Python alpha version to 3.15

Author: Paebbels

.github/workflows/Parameters.yml

@@ -259,8 +259,8 @@ jobs:
           disable_list =   "${{ inputs.disable_list }}".strip()
 
           currentMSYS2Version = "3.12"
-          currentAlphaVersion = "3.14"
-          currentAlphaRelease = "3.14.0-rc.3"
+          currentAlphaVersion = "3.15"
+          currentAlphaRelease = "3.15.0-a.1"
 
           if systems == "":
             print("::error title=Parameter::system_list is empty.")