.github: update Go versions to 1.25.x and 1.26.x

staticcheck v0.7.0 requires Go >= 1.25.0, which causes CI to fail on
Go 1.24.x. Update the test matrix to use Go 1.25.x and 1.26.x, the two
most recent stable release series.

Author: kevinburke

.github/workflows/ci.yml

@@ -4,7 +4,7 @@ jobs:
   test:
     strategy:
       matrix:
-        go-version: ['1.24.x', '1.25.x']
+        go-version: ['1.25.x', '1.26.x']
         platform: [ubuntu-latest]
     runs-on: ${{ matrix.platform }}
     steps: