Drop deprecated linters

.golangci.yml

@@ -37,9 +37,7 @@ linters:
     - unused # checks Go code for unused constants, variables, functions and types
     - govet # Vet examines Go source code and reports suspicious constructs, such as Printf calls whose arguments do not align with the format string
     - ineffassign # detects when assignments to existing variables are not used
-    - structcheck # finds unused struct fields
     - typecheck # Like the front-end of a Go compiler, parses and type-checks Go code
-    - varcheck # Finds unused global variables and constants
     - asciicheck # simple linter to check that your code does not contain non-ASCII identifiers
     - bodyclose # checks whether HTTP response body is closed successfully
     - durationcheck # check for two durations multiplied together