Test all versions in CI (#401)

Hi! Just checking out your project and I've noticed that you claim to support `>= 3.8`, but you never check other versions except 3.12 in CI.

https://github.com/kozistr/pytorch_optimizer/blob/3c02a48389c065f060a26e5486f7e702ff9fd17c/pyproject.toml#L33-L39

I think that it is important to be sure all version work :)
They can have different bugs.

Author: sobolevn

.github/workflows/ci.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.12']
+        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12', '3.13']
 
     steps:
     - uses: actions/checkout@v4