The speed of light is dependent

Light is an electromagnetic wave and does not require any material medium for its propagation.

The propagation of mechanical waves depends on the properties of the medium such as elasticity and inertia.

Since light is a non-mechanical wave, its speed does not depend on the elasticity and inertia of the medium.

The speed of light in a vacuum is given by $c = \dfrac{1}{\sqrt{\mu_0 \epsilon_0}}$ and in a medium by $v = \dfrac{1}{\sqrt{\mu \epsilon}}$, where $\mu$ and $\epsilon$ are the magnetic permeability and electric permittivity of the medium.

Therefore, the speed of light depends on neither elasticity nor inertia.