Update Layout Builder functional javascript tests now that local tasks are not required by the UI.

Problem/Motivation

Identified in #3002608: Remove contextual links not related to layout administration inside layout builder blocks

Many of Layout Builder's functional and functional Javascript include these no-longer-valid lines:

    // @todo The Layout Builder UI relies on local tasks; fix in
    //   https://www.drupal.org/project/drupal/issues/2917777.
    $this->drupalPlaceBlock('local_tasks_block');

They are no longer valid because:

• The UI does not rely on local tasks
• The scope of the issue mentioned in the @todo

Proposed resolution

If a test does not include any clicking on local task links, just remove the three lines mentioned above.

For tests that include clicking on local task links where the same outcome can be accomplished by navigating directly, change these tests to navigate directly to their destination instead of clicking local tasks, then remove those three lines..

If there's good reason to keep local tasks in a test, then just remove the @todo, as it is no longer relevant.

Remaining tasks

Refactor tests, review, commit.

User interface changes

N/A

API changes

N/A

Data model changes

N/A

Release notes snippet

N/A