For a non-zero complex number $z$, let $\arg (z)$ denote the principal argument of $z$, with $-\pi<\arg (z) \leq \pi$. Let $\omega$ be the cube root of unity for which $0<\arg (\omega)<\pi$. Let
$ \alpha=\arg \left(\sum_{n=1}^{2025}(-\omega)^n\right) $
Then the value of $\frac{3 \alpha}{\pi}$ is $\_\_\_\_$