Adjust dependencies for Python compatibility before and in 3.14, cc #136 (#139)

Author: PeterDaveHello

requirements.txt

@@ -1,9 +1,11 @@
 slack-bolt>=1.19.1,<2
 slack-sdk>=3.30.0,<4
 openai>=1.68.2,<2
-tiktoken>=0.9.0,<0.10
+# Keep the existing tiktoken range on pre-3.14 and allow 3.14 installs.
+tiktoken>=0.9.0,<0.10; python_version < "3.14"
+tiktoken>=0.12.0,<0.13; python_version >= "3.14"
 # https://github.com/Yelp/elastalert/issues/2306
 urllib3<2
-pillow>=10.4.0,<11
+pillow>=11.3.0,<12
 requests>=2.32,<3
 python-dotenv>=1.0.1,<2