deps(ember): upgrade to latest LTS (4.8.x)

[jayjayjpg]

Description of change

Closes #1005
Part of https://github.com/meroxa/product/issues/749

With this change, we're upgrading conduit/ui from ember@4.0.1 to the latest LTS ember@4.8.x. This way, conduit/ui can also upgrade to latest security patches provided to Ember until December 2023.

This upgrade includes several minor version bumps in order to benefit from a bug fix in @ember/data that just landed in the 4.9 release. The related bug prevented us from upgrading beyond ember@4.7 due to an error in identifying new data records wrapped with ember-changeset correctly (Assertion Failed: Expected to receive a stable Identifier to subscribe to).

In addition, this upgrade includes:

• pinned version definition for several dependencies to resolve a sub dependency mismatch between @embroider/macros and ember-cli-mirage
• explicit enablement of Ember prototype extensions, which have been deprecated recently, but which are still in our codebase for now

Resolutions

The following changes were made to upgrade:

• run ember-cli-update --to 4.8
• re-run rm -rf node_modules && yarn to remove the existing npm packages and start a fresh install
• run ember t -s to start the test suite and see errors related to the upgrade
• work through all of the errors mentioned below and re-build / re-run the test suite after each resolution to verify
• once tests pass, shut down the test server and re-run sudo yarn start to verify the changes locally at https://dev.meroxa.io

Build error @babel/template placeholder "SAMPLE_FEATURE_FLAG": Expected string substitution

• you should see the @embroider/macros error in your terminal window (Build failure)
• open the log file mentioned in the error output
  --> you should see the error stack trace pointing to the node_modules and you should see a reference to ember-cli-mirage
• pin resolutions for the following packages as follows in package.json:

"resolutions": {
 // ...
     "miragejs": "~0.1.47",
    "@embroider/macros": "^1.10.0",
    "@embroider/util": "^1.10.0",
    "ember-cli-babel": "^7.26.11",
    "ember-modifier": "^3.2.7"
 // ...
 }

• re-run rm -rf node_modules && yarn to remove the existing npm packages and start a fresh install

Blockers before merging

• tests

How to verify?

• checkout the feature branch and run the app locally
• browse around
• -> the app should work as expected and no errors should be thrown

Quick checks:

• I have followed the Code Guidelines.
• There is no other pull request for the same update/change.
• I have written unit tests.
• I have made sure that the PR is of reasonable size and can be easily reviewed.

[github-actions]

UI test coverage: 79.31%

🚨 No before coverage could be loaded

[github-actions]

UI test coverage: 79.31%

🚨 No before coverage could be loaded

[github-actions]

UI test coverage: 79.31%

🚨 No before coverage could be loaded