golangci-lint: Don't use deprecated config params

Replace deprecated golangci-lint configuration parameters with current
equivalents:

* `run.skip-files` => `issues.exclude-files`
* `run.skip-dirs` => `issues.exclude-dirs`

Signed-off-by: Arve Knudsen <arve.knudsen@gmail.com>

.golangci.yml

@@ -1,12 +1,5 @@
 run:
   timeout: 15m
-  skip-files:
-    # Skip autogenerated files.
-    - ^.*\.(pb|y)\.go$
-  skip-dirs:
-    # Copied it from a different source
-    - storage/remote/otlptranslator/prometheusremotewrite
-    - storage/remote/otlptranslator/prometheus
 
 output:
   sort-results: true
@@ -33,6 +26,13 @@ linters:
 
 issues:
   max-same-issues: 0
+  exclude-files:
+    # Skip autogenerated files.
+    - ^.*\.(pb|y)\.go$
+  exclude-dirs:
+    # Copied it from a different source
+    - storage/remote/otlptranslator/prometheusremotewrite
+    - storage/remote/otlptranslator/prometheus
   exclude-rules:
     - linters:
         - gocritic