update golangci-lint to v1.49.0

Also replaced deprecated linters:

    WARN [runner] The linter 'varcheck' is deprecated (since v1.49.0) due to: The owner seems to have abandoned the linter.  Replaced by unused.
    WARN [runner] The linter 'structcheck' is deprecated (since v1.49.0) due to: The owner seems to have abandoned the linter.  Replaced by unused.
    WARN [runner] The linter 'golint' is deprecated (since v1.41.0) due to: The repository of the linter has been archived by the owner.  Replaced by revive.
    WARN [runner] The linter 'interfacer' is deprecated (since v1.38.0) due to: The repository of the linter has been archived by the owner.
    WARN [runner] The linter 'deadcode' is deprecated (since v1.49.0) due to: The owner seems to have abandoned the linter.  Replaced by unused.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

.circleci/config.yml

@@ -50,8 +50,8 @@ jobs:
     steps:
     - checkout
     - go/install-golangci-lint:
-        prefix: v1.48.0
-        version: 1.48.0
+        prefix: v1.49.0
+        version: 1.49.0
     - go/install: {package: git}
     - run:
         name: Lint

.golangci.yml

@@ -32,7 +32,6 @@ linters:
   disable-all: true
   enable:
     - bodyclose
-    - deadcode
     - depguard
     - dogsled
     - errcheck
@@ -42,11 +41,9 @@ linters:
     - goconst
     - gofmt
     - goimports
-    - golint
     - gosimple
     - govet
     - ineffassign
-    - interfacer
     - lll
     - maintidx
     - misspell
@@ -56,13 +53,12 @@ linters:
     - nilnil
     - nolintlint
     - prealloc
+    - revive
     - staticcheck
-    - structcheck
     - stylecheck
     - typecheck
     - unconvert
     - unparam
     - unused
-    - varcheck
     - wastedassign
     - whitespace