Revert "Add PS 7 to UseCompatibleSyntax (PowerShell#1331)"

This reverts commit 1202f4e.

Author: Christoph Bergmeister

Rules/CompatibilityRules/UseCompatibleSyntax.cs

@@ -29,15 +29,12 @@ public class UseCompatibleSyntax : ConfigurableRule
 
         private static readonly Version s_v6 = new Version(6,0);
 
-        private static readonly Version s_v7 = new Version(7,0);
-
         private static readonly IReadOnlyList<Version> s_targetableVersions = new []
         {
             s_v3,
             s_v4,
             s_v5,
-            s_v6,
-            s_v7,
+            s_v6
         };
 
         /// <summary>
@@ -126,7 +123,7 @@ private static HashSet<Version> GetTargetedVersions(string[] versionSettings)
         {
             if (versionSettings == null || versionSettings.Length <= 0)
             {
-                return new HashSet<Version>(){ s_v5, s_v6, s_v7 };
+                return new HashSet<Version>(){ s_v5, s_v6 };
             }
 
             var targetVersions = new HashSet<Version>();
@@ -281,7 +278,7 @@ public override AstVisitAction VisitFunctionDefinition(FunctionDefinitionAst fun
             {
                 // Look for PowerShell workflows in the script
 
-                if (!(_targetVersions.Contains(s_v6) || _targetVersions.Contains(s_v7)))
+                if (!_targetVersions.Contains(s_v6))
                 {
                     return AstVisitAction.Continue;
                 }