Replace jest-puppeteer with Playwright

Advantages of the new Playwright setup:

1. It auto-detects whether a server is already running (no need for two
   separate npm scripts)
2. Browser installation is done in a separate command. Previously, it
   was done on installation of puppeteer which became difficult to debug
   when it timed out on remote build environments.
3. It requires much fewer dependencies (see diff of package-lock.json)

.github/workflows/ci.yaml

@@ -51,7 +51,7 @@ jobs:
           node-version: ${{ matrix.node }}
       - run: npm ci --loglevel verbose
       - run: npm run get-data
-      - run: npm run smoke-test:ci
+      - run: npm run smoke-test
 
   lint:
     runs-on: ubuntu-latest

.gitignore

@@ -16,5 +16,8 @@ node_modules/
 npm-debug.log
 *tgz
 
+### playwright ###
+.playwright/
+
 ### IDE ###
 .vscode/*

DEV_DOCS.md

@@ -53,8 +53,7 @@ From a fork: `git pull --rebase upstream master`
 We use the following libraries for all kinds of testing, so it'd help to read the docs to get familiar with their APIs and features:
 
 1. [`Jest`](https://github.com/facebook/jest)
-2. [`Puppeteer`](https://github.com/puppeteer/puppeteer/)
-3. [`Jest-Puppeteer`](https://github.com/smooth-code/jest-puppeteer)
+2. [`Playwright`](https://playwright.dev)
 
 When you submit a pull request to the auspice repository, certain tests will need to pass before it can be merged.
 
@@ -74,11 +73,13 @@ Run `npm run lint`. If there are issues run `npm run lint:fix`.
 
 Auspice used to have integration testing using jest + puppeteer, however this was removed in [PR 1672](https://github.com/nextstrain/auspice/pull/1672).
 Ideally this functionality will be brought back, and that PR would be a good place to start.
+If embarking on this journey, consider using Playwright since it is already used for smoke tests.
 
 #### For smoke tests
 
 1. Fetch the datasets with `npm run get-data`.
-2. Ensure you are **not** currently running the site locally, then run `npm run smoke-test:ci`.
+2. Install the testing browser with `npx playwright install chromium`.
+3. Run `npm run smoke-test`.
 
 
 #### Test Tips