Update Go test matrix to current versions (1.24-1.26)

.github/workflows/test.yml

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 627ac7b..c0c8ce8 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -14,9 +14,9 @@
           - macos-latest
           - windows-latest
         go:
-          - '1.23'
-          - '1.22'
-          - '1.21'
+          - '1.26'
+          - '1.25'
+          - '1.24'
     steps:
       - uses: actions/checkout@v6
       - uses: actions/setup-go@v6