[Flaky Tests]: Link Form Submission

The test passes consistently locally, but fails consistently in CI:

```
1) [chrome] › form_submission_tests.ts:909:1 › test following a link with [data-turbo-method] and [data-turbo=true] set when html[data-turbo=false]

  AssertionError: does not navigate the full page: expected 'Hello' to equal 'Form'

    918 |   await link.click()

    919 |

  > 920 |   assert.equal(await page.textContent("h1"), "Form", "does not navigate the full page")

        |          ^

    921 |   assert.equal(await page.textContent("#hello h2"), "Hello from a frame", "drives the turbo-frame")

    922 | })

    923 |

      at /home/runner/work/turbo/turbo/src/tests/functional/form_submission_tests.ts:920:10

2) [chrome] › form_submission_tests.ts:924:1 › test following a link with [data-turbo-method] and [data-turbo=true] set when Turbo.session.drive = false

  AssertionError: does not navigate the full page: expected 'Hello' to equal 'Form'

    932 |   await link.click()

    933 |

  > 934 |   assert.equal(await page.textContent("h1"), "Form", "does not navigate the full page")

        |          ^

    935 |   assert.equal(await page.textContent("#hello h2"), "Hello from a frame", "drives the turbo-frame")

    936 | })

    937 |

      at /home/runner/work/turbo/turbo/src/tests/functional/form_submission_tests.ts:934:10
```

As a precaution, escape the URL path to embedded into the `[href]`
attribute.

Additionally, execute CI with the GitHub Actions reporter.

.github/workflows/ci.yml

@@ -40,13 +40,6 @@ jobs:
     - name: Firefox Test
       run: yarn test:browser --project=firefox
 
-    - name: Upload test results
-      if: always()
-      uses: actions/upload-artifact@v2
-      with:
-        name: playwright-report
-        path: playwright-report
-
     - name: Publish dev build
       run: .github/scripts/publish-dev-build '${{ secrets.DEV_BUILD_GITHUB_TOKEN }}'
       if: ${{ github.event_name == 'push' }}

src/tests/fixtures/form.html

@@ -309,7 +309,7 @@ <h2>Frame: Form</h2>
     <form method="post" action="https://httpbin.org/post">
       <button id="submit-external">POST to https://httpbin.org/post</button>
     </form>
-     <a href="/__turbo/redirect?path=/src/tests/fixtures/frames/hello.html" data-turbo-method="post" data-turbo-frame="hello" id="turbo-method-post-to-targeted-frame">Turbo method post to targeted frame</a>
+     <a href="/__turbo/redirect?path=%2Fsrc%2Ftests%2Ffixtures%2Fframes%2Fhello.html" data-turbo-method="post" data-turbo-frame="hello" id="turbo-method-post-to-targeted-frame">Turbo method post to targeted frame</a>
     <turbo-frame id="hello"></turbo-frame>
     <hr>