[BUG] SKShader doesn't release all memory on Dispose()

[michaldobrodenka]

Description

I think the bug is in ToHarfBuzzBlob() extension - it doesn't dispose SKStreamAsset in all paths.

Code

It seems that this code leaks SKStreamAssets even if properly disposed:

    {
        public SKPaint Paint { get; set; }
        public SKShaper Shaper { get; set; }

        private bool disposedValue;

        public TextSegmentShaper(SKTypeface typeface, SKPaint fromPaint)
        {
            Paint = new SKPaint()
            {
                Style = fromPaint.Style,
                IsAntialias = fromPaint.IsAntialias,
                Color = fromPaint.Color,
                Typeface = typeface,
                TextSize = fromPaint.TextSize,
                TextAlign = fromPaint.TextAlign,
                SubpixelText = fromPaint.SubpixelText,
            };

            Shaper = new SKShaper(typeface);
        }

        protected virtual void Dispose(bool disposing)
        {
            if (!disposedValue)
            {
                Paint?.Dispose();
                Shaper?.Dispose();

                Paint = null;
                Shaper = null;

                disposedValue = true;
            }
        }```

### Expected Behavior

_No response_

### Actual Behavior

_No response_

### Version of SkiaSharp

3.116.0 (Current)

### Last Known Good Version of SkiaSharp

Other (Please indicate in the description)

### IDE / Editor

Visual Studio (Windows)

### Platform / Operating System

Windows

### Platform / Operating System Version

First observed bug on Android, but seems to be a problem also on Windows.

### Devices

_No response_

### Relevant Screenshots

_No response_

### Relevant Log Output

```shell

Code of Conduct

• I agree to follow this project's Code of Conduct

[github-actions]

Triage Summary

Labels will be applied to indicate the affected backends (Android and Metal), specific areas (SkiaSharp), reliability concerns, and operating systems (Windows-Classic and Android).

This issue is not identified as a regression; it appears to be a new bug related to memory management.

Additional remarks:

• The issue involves a memory leak with SKShader and SKStreamAsset, potentially causing reliability issues due to failure to release memory.

Detailed Summary and Actions

Summary of the triage:

• The issue affects the Android backend, indicating a specific platform relevance.
• It also pertains to Metal's rendering performance, suggesting broader implications for graphics.
• The memory leak is tied to the SkiaSharp library, particularly with SKShader and SKStreamAsset.
• This issue has reliability implications due to memory not being released properly, possibly causing crashes.
• A specific instance on Windows-Classic is also mentioned, connecting the issue to different operating systems.

Summary of the actions that will be performed:

Action	Item	Description
Apply Label	backend/Android	The issue was first observed on Android, indicating relevancy to the backend.
Apply Label	backend/Metal	The bug may affect rendering performance on Metal, relating to resource management.
Apply Label	area/SkiaSharp	The issue pertains to a memory leak involving SKShader and SKStreamAsset in SkiaSharp.
Apply Label	tenet/reliability	The issue describes a memory management bug that could lead to crashes or leaks, impacting reliability.
Apply Label	os/Windows-Classic	The memory leak in question is noted in the context of Windows, particularly with Visual Studio.
Apply Label	os/Android	The bug was first observed on Android, suggesting it may also affect users of this platform.

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