Use Python 3.13 and remove Python 3.7 workflow

Author: ahmedfgad

.github/workflows/main_py37.yml renamed to .github/workflows/main_py313.yml

@@ -1,4 +1,4 @@
-name: PyGAD PyTest / Python 3.7
+name: PyGAD PyTest / Python 3.13
 
 on:
   push:
@@ -15,10 +15,10 @@ jobs:
       - name: Checkout Pre-Built Action
         uses: actions/checkout@v3
 
-      - name: Setup Python 3.7
+      - name: Setup Python 3.13
         uses: actions/setup-python@v4
         with:
-          python-version: '3.7'
+          python-version: '3.13'
 
       - name: Install Dependencies
         run: |