LibGL: Implement glActiveTexture

Author: https://github.com/Quaker762
Commit: 573c1c82f7
Pull-request: https://github.com/SerenityOS/serenity/pull/7586
Reviewed-by: https://github.com/alimpfard
Reviewed-by: https://github.com/linusg
Reviewed-by: https://github.com/sunverwerth ✅

Userland/Libraries/LibGL/SoftwareGLContext.h

@@ -70,6 +70,7 @@ public:
     virtual void gl_tex_image_2d(GLenum target, GLint level, GLint internal_format, GLsizei width, GLsizei height, GLint border, GLenum format, GLenum type, const GLvoid* data) override;
     virtual void gl_tex_coord(GLfloat s, GLfloat t, GLfloat r, GLfloat q) override;
     virtual void gl_bind_texture(GLenum target, GLuint texture) override;
+    virtual void gl_active_texture(GLenum texture) override;
 
     virtual void present() override;