Disable flutter_portal tests

[b-luk]

Disable flutter_portal tests. The flutter_portal CI runs on an old Flutter SDK (3.10.0) and does not support patches on the current main channel Flutter SDK.

From https://github.com/flutter/tests/blob/main/README.md:

• The upstream repository that hosts the tests must be able to receive patches to support the main channel of Flutter. This means that CI on the upstream repository should use the main channel Flutter SDK.

@fzyzcjy

[gaaclarke]

lgtm

[gaaclarke]

@fzyzcjy this showed up because the customer tests script automatically runs dart fix on customer tests with the main channel. withOpacity() was replaced with withValues(alpha:) which has slightly different rounding logic for things like 0.5 which don't map cleaning into the 0-255 space. We tried to forward fix the test for you, but we couldn't because the tests are running against a pegged old version of Flutter, 3.10 which doesn't have access to the new API. Ultimately, running tests against channels other than main is a violation of the rules to being subscribed to customer tests as b-luk stated.

The easiest way to get these tests reenabled is to switch your github actions to work against the main channel instead. For your own testing against 3.10 and stable you'll have to move them into a different github action that isn't triggered by Flutter's customer testing.

[b-luk]

Let's wait a bit before landing this. If @fzyzcjy gets a quick fix for this, we can avoid some churn.

[fzyzcjy]

Hi, thanks for pinging me! Unfortunately I have a very tight DDL recently and do not have time to update it :( Feel free to just disable it currently and I will handle it later.