Remove K8s 1.12 from test matrix

Author: thegridman

.github/workflows/k8s-matrix.yaml

@@ -41,7 +41,6 @@ jobs:
           - kindest/node:v1.15.11@sha256:6cc31f3533deb138792db2c7d1ffc36f7456a06f1db5556ad3b6927641016f50
           - kindest/node:v1.14.10@sha256:6cd43ff41ae9f02bb46c8f455d5323819aec858b99534a290517ebc181b443c6
           - kindest/node:v1.13.12@sha256:214476f1514e47fe3f6f54d0f9e24cfb1e4cda449529791286c7161b7f9c08e7
-          - kindest/node:v1.12.10@sha256:faeb82453af2f9373447bb63f50bae02b8020968e0889c7fa308e19b348916cb
 
     steps:
     - uses: actions/checkout@v2