CI: update Go version

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

Author: AkihiroSuda

.github/workflows/main.yml

@@ -9,7 +9,7 @@ jobs:
   main:
     strategy:
       matrix:
-        go-version: [1.23.x, 1.24.x]
+        go-version: [oldstable, stable]
         platform: [ubuntu-latest, macos-latest, windows-latest]
     runs-on: ${{ matrix.platform }}
     steps:

.github/workflows/release.yml

@@ -8,7 +8,7 @@ jobs:
   release:
     strategy:
       matrix:
-        go-version: [1.24.x]
+        go-version: [stable]
         os: [ubuntu-24.04]
     runs-on: ${{ matrix.os }}
     timeout-minutes: 20