[tests only] Add linux types for buildkite-agent (ddev#2828)

These actually won't be used since we have github actions, travis-ci, and circleci for Linux. It was an experiment, but might as well keep the results.

.buildkite/linux-amd64.yml

@@ -0,0 +1,9 @@
+  - command: ".buildkite/test.sh"
+    agents:
+      - "os=linux"
+      - "architecture=amd64"
+    env:
+      BUILDKITE_CLEAN_CHECKOUT: true
+      BUILDKITE_BUILD_PATH: ~/tmp/buildkite_builds
+      BUILDKIT_PROGRESS: plain
+    parallelism: 1

.buildkite/linux-arm64.yml

@@ -0,0 +1,9 @@
+  - command: ".buildkite/test.sh"
+    agents:
+      - "os=linux"
+      - "architecture=arm64"
+    env:
+      BUILDKITE_CLEAN_CHECKOUT: true
+      BUILDKITE_BUILD_PATH: ~/tmp/buildkite_builds
+      BUILDKIT_PROGRESS: plain
+    parallelism: 1

.buildkite/macos_container.yml

@@ -2,6 +2,7 @@
     agents:
       - "os=macos"
       - "dockertype=dockerformac"
+      - "architecture=amd64"
     env:
       BUILDKITE_CLEAN_CHECKOUT: true
       BUILDKITE_BUILD_PATH: ~/tmp/buildkite_builds

.buildkite/test.sh

@@ -69,7 +69,9 @@ echo "--- running sanetestbot.sh"
 ( docker images | awk '/drud/ {print $1":"$2 }' | xargs -L1 docker pull ) || true
 
 # homebrew sometimes removes /usr/local/etc/my.cnf.d
-mkdir -p "$(brew --prefix)/etc/my.cnf.d"
+if command -v brew >/dev/null; then
+  mkdir -p "$(brew --prefix)/etc/my.cnf.d"
+fi
 
 echo "--- Running tests..."
 make test

.buildkite/windows10_container.yml

@@ -2,6 +2,7 @@
     agents:
       - "os=windows"
       - "dockertype=dockerforwindows"
+      - "architecture=amd64"
     env:
       BUILDKITE_CLEAN_CHECKOUT: true
     parallelism: 1

.buildkite/windows10dockerforwindows.yml

@@ -2,6 +2,7 @@
     agents:
       - "os=windows"
       - "dockertype=dockerforwindows"
+      - "architecture=amd64"
     env:
       BUILDKITE_CLEAN_CHECKOUT: true
       DDEV_TEST_USE_NFSMOUNT: true

.buildkite/wsl2.yml

@@ -1,6 +1,7 @@
   - command: ".buildkite/test.sh"
     agents:
       - "os=wsl2"
+      - "architecture=amd64"
     env:
       BUILDKITE_CLEAN_CHECKOUT: true
       BUILDKITE_BUILD_PATH: ~/tmp/buildkite_builds