fix: provider modern error unwrapping

Implement `errors.As` and `errors.Unwrap` to make `ErrorSet` compatible
with modern Go.

(This helps to correctly find matches in wrapper errors).

Signed-off-by: Andrey Smirnov <andrey.smirnov@siderolabs.com>

.dockerignore

@@ -1,8 +1,8 @@
 # THIS FILE WAS AUTOMATICALLY GENERATED, PLEASE DO NOT EDIT.
 #
-# Generated on 2020-09-01T21:14:08Z by kres ee90a80-dirty.
+# Generated on 2023-10-19T18:06:29Z by kres latest.
 
-**
+*
 !retry
 !go.mod
 !go.sum

.github/workflows/ci.yaml

@@ -0,0 +1,81 @@
+# THIS FILE WAS AUTOMATICALLY GENERATED, PLEASE DO NOT EDIT.
+#
+# Generated on 2023-10-19T18:06:29Z by kres latest.
+
+name: default
+concurrency:
+  group: ${{ github.event.label == null && github.head_ref || github.run_id }}
+  cancel-in-progress: true
+"on":
+  push:
+    branches:
+      - main
+      - release-*
+    tags:
+      - v*
+  pull_request:
+    branches:
+      - main
+      - release-*
+jobs:
+  default:
+    permissions:
+      contents: write
+      packages: write
+    runs-on:
+      - self-hosted
+      - generic
+    if: (!startsWith(github.head_ref, 'renovate/') && !startsWith(github.head_ref, 'dependabot/'))
+    services:
+      buildkitd:
+        image: moby/buildkit:v0.12.2
+        options: --privileged
+        ports:
+          - 1234:1234
+        volumes:
+          - /var/lib/buildkit/${{ github.repository }}:/var/lib/buildkit
+          - /usr/etc/buildkit/buildkitd.toml:/etc/buildkit/buildkitd.toml
+    steps:
+      - name: checkout
+        uses: actions/checkout@v4
+      - name: Unshallow
+        run: |
+          git fetch --prune --unshallow
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+        with:
+          driver: remote
+          endpoint: tcp://localhost:1234
+      - name: base
+        run: |
+          make base
+      - name: unit-tests
+        run: |
+          make unit-tests
+      - name: unit-tests-race
+        run: |
+          make unit-tests-race
+      - name: coverage
+        run: |
+          make coverage
+      - name: lint
+        run: |
+          make lint
+      - name: Generate Checksums
+        if: startsWith(github.ref, 'refs/tags/')
+        run: |
+          sha256sum _out/* > _out/sha256sum.txt
+          sha512sum _out/* > _out/sha512sum.txt
+      - name: release-notes
+        if: startsWith(github.ref, 'refs/tags/')
+        run: |
+          make release-notes
+      - name: Release
+        if: startsWith(github.ref, 'refs/tags/')
+        uses: crazy-max/ghaction-github-release@v2
+        with:
+          body_path: _out/RELEASE_NOTES.md
+          draft: "true"
+          files: |-
+            _out/*
+            _out/sha*.txt