chore: use go1.18.3 (#816)

This diff changes all github actions and mk to use go1.18.3.

That's what I am using locally.

Also, both oohttp and oocrypto are on go1.18.3 already.

.github/workflows/netxlite.yml

@@ -13,7 +13,7 @@ jobs:
     runs-on: "${{ matrix.os }}"
     strategy:
       matrix:
-        go: [ "1.18.2" ]
+        go: [ "1.18.3" ]
         os: [ "ubuntu-20.04", "windows-2019", "macos-10.15" ]
     steps:
       - uses: magnetikonline/action-golang-cache@v2