LibWeb/WebGL: Make Context::activate() non-virtual

This method is only relevant for AccelGfx so no reason to keep it
virtual.

Userland/Libraries/LibWeb/WebGL/OpenGLContext.cpp

@@ -20,7 +20,7 @@ namespace Web::WebGL {
 #ifdef HAS_ACCELERATED_GRAPHICS
 class AccelGfxContext : public OpenGLContext {
 public:
-    virtual void activate() override
+    void activate()
     {
         m_context->activate();
     }
@@ -172,11 +172,6 @@ private:
 #ifdef AK_OS_SERENITY
 class LibGLContext : public OpenGLContext {
 public:
-    virtual void activate() override
-    {
-        GL::make_context_current(m_context);
-    }
-
     virtual void present(Gfx::Bitmap&) override
     {
         m_context->present();

Userland/Libraries/LibWeb/WebGL/OpenGLContext.h

@@ -15,7 +15,6 @@ class OpenGLContext {
 public:
     static OwnPtr<OpenGLContext> create(Gfx::Bitmap&);
 
-    virtual void activate() = 0;
     virtual void present(Gfx::Bitmap&) = 0;
     void clear_buffer_to_default_values();