fix(tests): follow custom-html docroot move

tests/custom-html/functional/test_content_roundtrip.py

@@ -23,11 +23,11 @@ def test_content_roundtrip(live_app):
     exact bytes round-trip. Non-vacuous: a stale page or misrouted backend would not return our
     randomly-generated content."""
     marker = f"ccci-roundtrip-{uuid.uuid4().hex}"
-    # written into the served volume; nginx routes /<filename> to /usr/share/nginx/html/<filename>
+    # written into the served volume; nginx routes /<filename> to /srv/www/html/<filename>
     filename = f"ccci-roundtrip-{uuid.uuid4().hex[:12]}.txt"
     lifecycle.exec_in_app(
         live_app,
-        ["sh", "-c", f"printf %s {marker} > /usr/share/nginx/html/{filename}"],
+        ["sh", "-c", f"printf %s {marker} > /srv/www/html/{filename}"],
     )
 
     url = f"https://{live_app}/{filename}"

tests/custom-html/functional/test_content_type_header.py

@@ -40,7 +40,7 @@ def test_content_type_html_and_txt(live_app):
     body = "hello"
     for name in (html_name, txt_name):
         lifecycle.exec_in_app(
-            live_app, ["sh", "-c", f"printf %s {body} > /usr/share/nginx/html/{name}"]
+            live_app, ["sh", "-c", f"printf %s {body} > /srv/www/html/{name}"]
         )
 
     s_html, h_html = _head(f"https://{live_app}/{html_name}")