build(deps): bump github.com/docker/distribution

Bumps [github.com/docker/distribution](https://github.com/docker/distribution) from 2.7.1+incompatible to 2.8.0+incompatible.
- [Release notes](https://github.com/docker/distribution/releases)
- [Commits](https://github.com/docker/distribution/compare/v2.7.1...v2.8.0)

---
updated-dependencies:
- dependency-name: github.com/docker/distribution
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

vendor/github.com/docker/distribution/.golangci.yml

@@ -0,0 +1,20 @@
+linters:
+  enable:
+    - structcheck
+    - varcheck
+    - staticcheck
+    - unconvert
+    - gofmt
+    - goimports
+    - golint
+    - ineffassign
+    - vet
+    - unused
+    - misspell
+  disable:
+    - errcheck
+
+run:
+  deadline: 2m
+  skip-dirs:
+    - vendor