Update environment.yml to match English repo versions

Updates:
- jupyter-book: 1.0.3 → 1.0.4post1
- quantecon-book-theme: 0.10.0 → 0.14.0
- sphinx-tojupyter: 0.3.0 → 0.6.0
- sphinx-exercise: 1.0.1 → 1.2.1
- sphinxcontrib-youtube: 1.3.0 → 1.4.1

Removed (no longer in English repo):
- sphinx-reredirects
- sphinx-proof
- ghp-import

Kept for authors:
- jupyterlab-myst
- jupytext

Author: mmcky

environment.yml

@@ -6,17 +6,13 @@ dependencies:
   - anaconda=2025.06
   - pip
   - pip:
-    - jupyter-book==1.0.3
-    - quantecon-book-theme==0.10.0
-    - sphinx-tojupyter==0.3.0
+    - jupyter-book==1.0.4post1
+    - quantecon-book-theme==0.14.0
+    - sphinx-tojupyter==0.6.0
     - sphinxext-rediraffe==0.2.7
-    - sphinx-reredirects==0.1.4
-    - sphinx-exercise==1.0.1
-    - sphinx-proof==0.2.1
-    - ghp-import==1.1.0
-    - sphinxcontrib-youtube==1.3.0 #Version 1.3.0 is required as quantecon-book-theme is only compatible with sphinx<=5
+    - sphinx-exercise==1.2.1
+    - sphinxcontrib-youtube==1.4.1
     - sphinx-togglebutton==0.3.2
     # Author Requirements
     - jupyterlab-myst
     - jupytext
-