Remove Go 1.21 from test matrix (requires 1.22)

Change-Id: If5fbe80714c6706a4c13736d1252c1244dcd7d4d

Author: andmat900

.github/workflows/main.yml

@@ -35,7 +35,7 @@ jobs:
     strategy:
       matrix:
         # Since we have 1.21 in the go.mod file, but toolchain is go1.22.1
-        go-version: [ '1.21', '1.22.1' ]
+        go-version: [ '1.22.1' ]
     steps:
       - uses: actions/checkout@v6
       - name: Setup Go ${{ matrix.go-version }}