Use collection initializers

Author: fdij

src/ProgressOnderwijsUtils.Analyzers/MustUseExpressionResultAnalyzer.cs

@@ -21,7 +21,7 @@ public sealed class MustUseExpressionResultAnalyzer : DiagnosticAnalyzer
     );
 
     public override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics
-        => ImmutableArray.Create(Rule);
+        => [Rule];
 
     public override void Initialize(AnalysisContext context)
     {

src/ProgressOnderwijsUtils/Collections/ProjectingEqualityComparer.cs

@@ -15,7 +15,7 @@ public sealed class ProjectingEqualityComparer<T>
     ProjectingEqualityComparer(EqualsComparer[] equality, HashComputation[] hash)
         => (Equality, Hash) = (equality, hash);
 
-    public ProjectingEqualityComparer() : this(Array.Empty<EqualsComparer>(), Array.Empty<HashComputation>()) { }
+    public ProjectingEqualityComparer() : this([], []) { }
 
     public ProjectingEqualityComparer<T> AddKeyColumn<TPart>(Func<T, TPart> part, IEqualityComparer<TPart> partComparer)
         => AddKey_WithoutColumn(([DisallowNull] a, [DisallowNull] b) => partComparer.Equals(part(a), part(b)), ([DisallowNull] o) => part(o) is { } nonNull ? partComparer.GetHashCode(nonNull) : 0);