Update method modifiers to address CA1822 (#48551)

* Update method modifiers to address CA1822

* Fix upstream affected methods

Author: mthalman

src/Framework/AspNetCoreAnalyzers/src/Analyzers/Infrastructure/RoutePattern/RoutePatternParser.cs

@@ -373,7 +373,7 @@ private static void ValidateNoConsecutiveSeparators(RoutePatternCompilationUnit
         }
     }
 
-    private void CollectDiagnostics(RoutePatternNode node, HashSet<EmbeddedDiagnostic> seenDiagnostics, IList<EmbeddedDiagnostic> diagnostics)
+    private static void CollectDiagnostics(RoutePatternNode node, HashSet<EmbeddedDiagnostic> seenDiagnostics, IList<EmbeddedDiagnostic> diagnostics)
     {
         foreach (var child in node)
         {

src/Framework/AspNetCoreAnalyzers/src/Analyzers/RouteEmbeddedLanguage/FrameworkParametersCompletionProvider.cs

@@ -455,30 +455,6 @@ private static void ProvideCompletions(EmbeddedCompletionContext context, Syntax
         }
     }
 
-    private (RoutePatternNode parent, RoutePatternToken Token)? FindToken(RoutePatternNode parent, VirtualChar ch)
-    {
-        foreach (var child in parent)
-        {
-            if (child.IsNode)
-            {
-                var result = FindToken(child.Node, ch);
-                if (result != null)
-                {
-                    return result;
-                }
-            }
-            else
-            {
-                if (child.Token.VirtualChars.Contains(ch))
-                {
-                    return (parent, child.Token);
-                }
-            }
-        }
-
-        return null;
-    }
-
     private readonly struct RoutePatternItem
     {
         public readonly string DisplayText;

src/Framework/AspNetCoreAnalyzers/src/Analyzers/RouteEmbeddedLanguage/RoutePatternCompletionProvider.cs

@@ -163,7 +163,7 @@ not CompletionTriggerKind.InvokeAndCommitIfUnique and
         context.IsExclusive = true;
     }
 
-    private void ProvideCompletions(EmbeddedCompletionContext context)
+    private static void ProvideCompletions(EmbeddedCompletionContext context)
     {
         var result = GetCurrentToken(context);
         if (result == null)
@@ -216,7 +216,7 @@ private void ProvideCompletions(EmbeddedCompletionContext context)
         }
     }
 
-    private (RoutePatternNode Parent, RoutePatternToken Token)? GetCurrentToken(EmbeddedCompletionContext context)
+    private static (RoutePatternNode Parent, RoutePatternToken Token)? GetCurrentToken(EmbeddedCompletionContext context)
     {
         var previousVirtualCharOpt = context.RouteUsage.RoutePattern.Text.Find(context.Position - 1);
         if (previousVirtualCharOpt == null)
@@ -279,7 +279,7 @@ private static void ProvidePolicyNameCompletions(EmbeddedCompletionContext conte
         }
     }
 
-    private (RoutePatternNode Parent, RoutePatternToken Token)? FindToken(RoutePatternNode parent, VirtualChar ch)
+    private static (RoutePatternNode Parent, RoutePatternToken Token)? FindToken(RoutePatternNode parent, VirtualChar ch)
     {
         foreach (var child in parent)
         {

src/Http/Routing/src/Tree/LinkGenerationDecisionTree.cs

@@ -104,7 +104,7 @@ public IList<OutboundMatchResult> GetMatches(RouteValueDictionary values, RouteV
     //  match.
     //
     // The decision tree uses a tree data structure to execute these rules across all candidates at once.
-    private void Walk(
+    private static void Walk(
         List<OutboundMatchResult> results,
         RouteValueDictionary values,
         RouteValueDictionary ambientValues,
@@ -233,7 +233,7 @@ internal string DebuggerDisplayString
         }
     }
 
-    private void FlattenTree(Stack<string> branchStack, StringBuilder sb, DecisionTreeNode<OutboundMatch> node)
+    private static void FlattenTree(Stack<string> branchStack, StringBuilder sb, DecisionTreeNode<OutboundMatch> node)
     {
         // leaf node
         if (node.Criteria.Count == 0)