vendor: update buildkit to v0.15.0-rc1

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/github.com/gofrs/flock/.golangci.yml

@@ -0,0 +1,114 @@
+run:
+  timeout: 10m
+
+linters:
+  enable:
+    - asasalint
+    - bidichk
+    - dogsled
+    - dupword
+    - durationcheck
+    - err113
+    - errname
+    - errorlint
+    - fatcontext
+    - forbidigo
+    - gocheckcompilerdirectives
+    - gochecknoinits
+    - gocritic
+    - godot
+    - godox
+    - gofumpt
+    - goheader
+    - goimports
+    - gomoddirectives
+    - goprintffuncname
+    - gosec
+    - inamedparam
+    - interfacebloat
+    - ireturn
+    - mirror
+    - misspell
+    - nolintlint
+    - revive
+    - stylecheck
+    - tenv
+    - testifylint
+    - thelper
+    - unconvert
+    - unparam
+    - usestdlibvars
+    - whitespace
+
+linters-settings:
+  misspell:
+    locale: US
+  godox:
+    keywords:
+      - FIXME
+  goheader:
+    template: |-
+      Copyright 2015 Tim Heckman. All rights reserved.
+      Copyright 2018-{{ YEAR }} The Gofrs. All rights reserved.
+      Use of this source code is governed by the BSD 3-Clause
+      license that can be found in the LICENSE file.
+  gofumpt:
+    extra-rules: true
+  gocritic:
+    enabled-tags:
+      - diagnostic
+      - style
+      - performance
+    disabled-checks:
+      - paramTypeCombine # already handle by gofumpt.extra-rules
+      - whyNoLint # already handle by nonolint
+      - unnamedResult
+      - hugeParam
+      - sloppyReassign
+      - rangeValCopy
+      - octalLiteral
+      - ptrToRefParam
+      - appendAssign
+      - ruleguard
+      - httpNoBody
+      - exposedSyncMutex
+
+  revive:
+    rules:
+      - name: struct-tag
+      - name: blank-imports
+      - name: context-as-argument
+      - name: context-keys-type
+      - name: dot-imports
+      - name: error-return
+      - name: error-strings
+      - name: error-naming
+      - name: exported
+      - name: if-return
+      - name: increment-decrement
+      - name: var-naming
+      - name: var-declaration
+      - name: package-comments
+      - name: range
+      - name: receiver-naming
+      - name: time-naming
+      - name: unexported-return
+      - name: indent-error-flow
+      - name: errorf
+      - name: empty-block
+      - name: superfluous-else
+      - name: unused-parameter
+      - name: unreachable-code
+      - name: redefines-builtin-id
+
+issues:
+  exclude-use-default: true
+  max-issues-per-linter: 0
+  max-same-issues: 0
+
+output:
+  show-stats: true
+  sort-results: true
+  sort-order:
+    - linter
+    - file