Blacklist ioutil pkg in golangci-lint

This is to prevent anyone from accidentally importing the pkg

Signed-off-by: Abhinav Nair <11939846+abhinavnair@users.noreply.github.com>

.golangci.yml

@@ -7,6 +7,7 @@ linters:
   disable-all: true
   enable:
     - deadcode
+    - depguard
     - errcheck
     - gocyclo
     - gofmt
@@ -26,6 +27,13 @@ linters:
     - unused
     - varcheck
 linters-settings:
+  depguard:
+    list-type: blacklist
+    include-go-root: true
+    packages:
+      # The io/ioutil package has been deprecated.
+      # https://go.dev/doc/go1.16#ioutil
+      - io/ioutil
   gocyclo:
     min-complexity: 16
   lll: