Minor AOT fixes and .NET 7 fixes.

Author: JimBobSquarePants

src/ImageSharp/Formats/Webp/Lossless/Vp8LEncoder.cs

@@ -502,7 +502,7 @@ private CrunchConfig[] EncoderAnalyze(ReadOnlySpan<uint> bgra, int width, int he
             doNotCache = true;
 
             // Go brute force on all transforms.
-            foreach (EntropyIx entropyIx in Enum.GetValues(typeof(EntropyIx)).Cast<EntropyIx>())
+            foreach (EntropyIx entropyIx in Enum.GetValues<EntropyIx>())
             {
                 // We can only apply kPalette or kPaletteAndSpatial if we can indeed use a palette.
                 if ((entropyIx != EntropyIx.Palette && entropyIx != EntropyIx.PaletteAndSpatial) || usePalette)

src/ImageSharp/Metadata/Profiles/ICC/IccReader.cs

@@ -88,9 +88,9 @@ private static IccTagDataEntry[] ReadTagData(IccDataReader reader)
         foreach (IccTagTableEntry tag in tagTable)
         {
             IccTagDataEntry entry;
-            if (store.ContainsKey(tag.Offset))
+            if (store.TryGetValue(tag.Offset, out IccTagDataEntry? value))
             {
-                entry = store[tag.Offset];
+                entry = value;
             }
             else
             {