.github/workflows: prebuilt integration test artifacts (#2954)

This PR restructures the integration tests and prebuilds all common assets used in all tests:

Headscale and Tailscale HEAD image
hi binary that is used to run tests
go cache is warmed up for compilation of the test
This essentially means we spend 6-10 minutes building assets before any tests starts, when that is done, all tests can just sprint through.

It looks like we are saving 3-9 minutes per test, and since we are limited to running max 20 concurrent tests across the repo, that means we had a lot of double work.

There is currently 113 checks, so we have to do five runs of 20, and the saving should be quite noticeable! I think the "worst case" saving would be 20+min and "best case" probably towards an hour.

.github/workflows/build.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     permissions: write-all
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
           fetch-depth: 2
       - name: Get changed files
@@ -29,13 +29,12 @@ jobs:
               - '**/*.go'
               - 'integration_test/'
               - 'config-example.yaml'
-      - uses: nixbuild/nix-quick-install-action@889f3180bb5f064ee9e3201428d04ae9e41d54ad # v31
+      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
         if: steps.changed-files.outputs.files == 'true'
       - uses: nix-community/cache-nix-action@135667ec418502fa5a3598af6fb9eb733888ce6a # v6.1.3
         if: steps.changed-files.outputs.files == 'true'
         with:
-          primary-key:
-            nix-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('**/*.nix',
+          primary-key: nix-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('**/*.nix',
             '**/flake.lock') }}
           restore-prefixes-first-match: nix-${{ runner.os }}-${{ runner.arch }}
 
@@ -55,7 +54,7 @@ jobs:
           exit $BUILD_STATUS
 
       - name: Nix gosum diverging
-        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
+        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
         if: failure() && steps.build.outcome == 'failure'
         with:
           github-token: ${{secrets.GITHUB_TOKEN}}
@@ -67,7 +66,7 @@ jobs:
               body: 'Nix build failed with wrong gosum, please update "vendorSha256" (${{ steps.build.outputs.OLD_HASH }}) for the "headscale" package in flake.nix with the new SHA: ${{ steps.build.outputs.NEW_HASH }}'
             })
 
-      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+      - uses: actions/upload-artifact@330a01c490aca151604b8cf639adc76d48f6c5d4 # v5.0.0
         if: steps.changed-files.outputs.files == 'true'
         with:
           name: headscale-linux
@@ -82,22 +81,20 @@ jobs:
           - "GOARCH=arm64 GOOS=darwin"
           - "GOARCH=amd64 GOOS=darwin"
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
-      - uses: nixbuild/nix-quick-install-action@889f3180bb5f064ee9e3201428d04ae9e41d54ad # v31
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
+      - uses: nixbuild/nix-quick-install-action@2c9db80fb984ceb1bcaa77cdda3fdf8cfba92035 # v34
       - uses: nix-community/cache-nix-action@135667ec418502fa5a3598af6fb9eb733888ce6a # v6.1.3
         with:
-          primary-key:
-            nix-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('**/*.nix',
+          primary-key: nix-${{ runner.os }}-${{ runner.arch }}-${{ hashFiles('**/*.nix',
             '**/flake.lock') }}
           restore-prefixes-first-match: nix-${{ runner.os }}-${{ runner.arch }}
 
       - name: Run go cross compile
         env:
           CGO_ENABLED: 0
-        run:
-          env ${{ matrix.env }} nix develop --command -- go build -o "headscale"
+        run: env ${{ matrix.env }} nix develop --command -- go build -o "headscale"
           ./cmd/headscale
-      - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4.6.2
+      - uses: actions/upload-artifact@330a01c490aca151604b8cf639adc76d48f6c5d4 # v5.0.0
         with:
           name: "headscale-${{ matrix.env }}"
           path: "headscale"