DPC-4438 Check static site for 508 compliance via github actions (#133)

## 🎫 Ticket

https://jira.cms.gov/browse/DPC-4438

## 🛠 Changes

Added check_508_compliance workflow.

## ℹ️ Context

We are moving our jobs from Jenkins to github actions. This is a clone
of
[Jenkinsfile.static_site_508_compliance](https://github.com/CMSgov/dpc-ops/blob/main/jenkins_files/Jenkinsfile.static_site_508_compliance)

## 🧪 Validation
Forced run worked:
https://github.com/CMSgov/dpc-static-site/actions/runs/12380895523
Forced run with failure (running on ubuntu-latest meant it was blocked,
so it tested the Cloudfront 403 response):
https://github.com/CMSgov/dpc-static-site/actions/runs/12379865142/job/34554969116

.github/workflows/check_508_compliance.yml

@@ -0,0 +1,34 @@
+name: Check 508 Compliance
+
+on:
+  schedule:
+    - cron: 17 8 * * 1
+  workflow_dispatch:
+    inputs:
+      target_host:
+        description: Check where?
+        required: true
+        default: 'https://stage.dpc.cms.gov'
+        type: choice
+        options:
+          - 'https://stage.dpc.cms.gov'
+          - 'https://dpc.cms.gov'
+
+jobs:
+  compliance_check:
+    name: Compliance Check
+    runs-on: self-hosted
+    steps:
+      - name: Run Axe Check
+        env:
+          TARGET_BASE_URL: ${{ inputs.target_host || 'https://stage.dpc.cms.gov' }}
+        run: |
+          TARGETS_TO_SCAN="${TARGET_BASE_URL}"
+          TARGETS_TO_SCAN="${TARGETS_TO_SCAN} ${TARGET_BASE_URL}/faq.html"
+          TARGETS_TO_SCAN="${TARGETS_TO_SCAN} ${TARGET_BASE_URL}/data.html"
+          TARGETS_TO_SCAN="${TARGETS_TO_SCAN} ${TARGET_BASE_URL}/pilot.html"
+          TARGETS_TO_SCAN="${TARGETS_TO_SCAN} ${TARGET_BASE_URL}/docsV1.html"
+          TARGETS_TO_SCAN="${TARGETS_TO_SCAN} ${TARGET_BASE_URL}/docsV2.html" 
+          TARGETS_TO_SCAN="${TARGETS_TO_SCAN} ${TARGET_BASE_URL}/updates.html"
+          docker run --init --rm --cap-add=SYS_ADMIN orenfromberg/axe-puppeteer-ci:1.0.0@sha256:f83527a3ae8ab74088c001abfe44836946ba73f0afbbf460447f8a0c40281e70 $TARGETS_TO_SCAN
+