Add / switch to Go 1.18

Switch to Go 1.18 as the default Go version.

Support for Go 1.16 is removed by the next commit.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

.github/workflows/test.yml

@@ -21,13 +21,13 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        go-version: [1.16.x, 1.17.x, 1.18.0-beta1]
+        go-version: [1.16.x, 1.17.x, 1.18.x]
         rootless: ["rootless", ""]
         race: ["-race", ""]
         criu: [""]
         include:
           # Also test against latest criu-dev
-          - go-version: 1.17.x
+          - go-version: 1.18.x
             rootless: ""
             race: ""
             criu: "criu-dev"

.github/workflows/validate.yml

@@ -8,7 +8,7 @@ on:
       - release-*
   pull_request:
 env:
-  GO_VERSION: 1.17.x
+  GO_VERSION: 1.18.x
 
 jobs: