Remove Python 3.9 support (#5081)

Summary:
X-link: https://github.com/facebookresearch/FBGEMM/pull/2088

- Remove Python 3.9 support, following PyTorch nightlies

Pull Request resolved: #5081

Reviewed By: spcyppt

Differential Revision: D86168579

Pulled By: q10

fbshipit-source-id: f15a5107ab9f86c7c07e704f510faab312bac858

Author: q10

.github/workflows/fbgemm_gpu_ci_cpu.yml

@@ -75,7 +75,7 @@ jobs:
           { arch: arm, instance: "linux.arm64.m7g.4xlarge" },
         ]
         build-target: [ "default" ]
-        python-version: [ "3.9", "3.10", "3.11", "3.12", "3.13" ]
+        python-version: [ "3.10", "3.11", "3.12", "3.13" ]
         compiler: [ "gcc", "clang" ]
 
     steps:
@@ -149,7 +149,7 @@ jobs:
           { arch: arm, instance: "linux.arm64.m7g.4xlarge", timeout: 30 },
         ]
         build-target: [ "default" ]
-        python-version: [ "3.9", "3.10", "3.11", "3.12", "3.13" ]
+        python-version: [ "3.10", "3.11", "3.12", "3.13" ]
         compiler: [ "gcc", "clang" ]
     needs: build_artifact