ci: add go 1.25

Switch from go 1.24 to go 1.25 where we use a single go version.

Drop go 1.23, add go 1.25 to the test matrix.

(Note most testing is done in a VM job which uses whatever Go version is
shipped with a distro).

Signed-off-by: Kir Kolyshkin <[email protected]>

Author: kolyshkin

.github/workflows/validate.yml

@@ -33,7 +33,7 @@ jobs:
       - uses: actions/checkout@v5
       - uses: actions/setup-go@v6
         with:
-          go-version: 1.24.x
+          go-version: 1.25.x
       - uses: golangci/golangci-lint-action@v8
         with:
           version: v2.5
@@ -61,7 +61,7 @@ jobs:
       - uses: actions/checkout@v5
       - uses: actions/setup-go@v6
         with:
-          go-version: 1.24.x
+          go-version: 1.25.x
       - uses: golangci/golangci-lint-action@v8
         with:
           version: v2.5
@@ -72,7 +72,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        go-version: [1.19.x, 1.23.x, 1.24.x]
+        go-version: [1.19.x, 1.24.x, 1.25.x]
         race: ["-race", ""]
     runs-on: ubuntu-24.04
     steps: