thorvg: Update to 0.15.16

[Chubercik]

https://github.com/thorvg/thorvg/releases/tag/v0.15.14

Changes

• [Core] Corrected an incorrect fill rule option in text rendering.
• [Core] Fixed incorrect calculation in multiple mask applications.
• [Core] Improved radial gradient handling to conform with SVG 1.1 and address edge cases.
• [CPU] Improved the DropShadow effect stability.
• [CPU] Updated the SoftLight blending equation to align with the W3C specification.
• [CPU] Added proper support for zero-size blur in DropShadow effects.
• [CPU] Revised texture clipping logic to correctly support shapes with inner corners.
• [CPU] Fixed an issue where lines were missing when a picture was rotated 90 degrees.
• [GL/ES] Fixed broken clipping behavior.
• [Lottie] Increased the quality level of GaussianBlur and DropShadow from low to medium.
• [Lottie] Adjusted DropShadow distance to match Adobe After Effects behavior.
• [Lottie] Fixed missing offset corners when using miter joins.
• [Lottie] Ensured proper star/polygon closure to prevent artifacts from inaccurate point comparisons.
• [Lottie] Corrected an issue causing inaccurate opacity when using the Repeater property.
• [Lottie] Fixed a specification mismatch when a null layer was applied to layer masking.
• [SVG] Fix the nested use nodes.
• [Additional Notes] Removed Lena resources previously used in ThorVG.

[Chubercik]

Updated & rebased, ready to go 🐾

[Repiteo]

Thanks!