Restore Python 3.9 support with split requests constraint

Reverts the 3.9 drop. Python 3.9 installs stay on requests 2.32.5
(no upstream backport for CVE-2026-25645 exists) while Python >=3.10
gets 2.33.1.

https://claude.ai/code/session_01Nsf9RKZvau6jx2vA8MULoD

Author: claude

poetry.lock

@@ -9,16 +9,19 @@ readme = "README.md"
 robusta = "robusta_cli.main:app"
 
 [tool.poetry.dependencies]
-python = "^3.10, <3.13"
+python = "^3.9, <3.13"
 typer = "^0.12.3"
 pyyaml = "^6.0.1"
 click-spinner = "^0.1.10"
-cryptography = "46.0.7"
+cryptography = {version = "46.0.7", python = ">=3.9.2,<3.13"}
 dpath = "^2.0.5"
 pydantic = "^1.0"
 slack-sdk = "^3"
 pyjwt = "^2.4.0"
-requests = "^2.33.0"
+requests = [
+    {version = "^2.32.4", python = "<3.10"},
+    {version = "^2.33.0", python = ">=3.10"}
+]
 certifi = "2024.7.4"
 types-toml = "^0.10.2"
 toml = "^0.10.2"