set a non-root user for containers (#2496)

* change root user in dockerfile

* build container on push/pr

* grab docker build params from env

* consolidate container build

* rm unused container build workflow/script

* cleanup ci

* set user for earthly container build

* rm ci docker build for develop branch

* checkout full repo for docker builds

* read earthly push from env

* cleanup ci

* rm unsupported option for actions/checkout@v3

* check dockerfile in ci

* add dockerfile build to earthfile

* authenticate to GH only on schedule builds

* accurate name for dev container builder script

* add note to the dockerfile about earthfile

* document dev build process more clearly

.github/workflows/container-lint.yml

@@ -0,0 +1,28 @@
+name: Lint
+
+on:
+  push:
+    branches:
+      - webv2
+    paths:
+      - 'Dockerfile'
+  pull_request:
+    branches:
+      - webv2
+    paths:
+      - 'Dockerfile'
+
+jobs:
+  trivy:
+    name: Dockerfile
+    runs-on: ubuntu-latest
+    container:
+      image: aquasec/trivy
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Check critical issues
+        run: trivy config --exit-code 1 --severity "HIGH,CRITICAL" ./Dockerfile
+
+      - name: Check non-critical issues
+        run: trivy config --severity "LOW,MEDIUM" ./Dockerfile