fix: Deprecated warnings fixed

[CurtlyCritchlow]

Fixes #905

- What I did

• Replace depreciated withOpacity method with withValues in at_common_flutter, at_onboarding_flutter. These fixes on the beta channel results in errors on the stable channel.

- How I did it

- How to verify it

- Description for the changelog

[cpswan]

Thanks @CurtlyCritchlow

My inclination here is to hold off on making these changes until Flutter 3.25 is stable. We have --no-fatal-infos for the tests that run against stable. So the deprecation warnings won't cause stable channel static analysis to fail. We can then make changes that will work for both 3.25 and 3.26 as they'll both support withvalues.

👀 @gkc @XavierChanth

[CurtlyCritchlow]

@cpswan Can I publish the packages one at a time before merging it to main. Our package too dependent on each other to update all the packages at once and then publish after merge. The static analysis will keep failing. You can look at_backup_flutter stable.

[XavierChanth]

@cpswan Can I publish the packages one at a time before merging it to main. Our package too dependent on each other to update all the packages at once and then publish after merge. The static analysis will keep failing. You can look at_backup_flutter stable.

Wait for review approval before publishing, I can review in a few hours

[CurtlyCritchlow]

static analysis will keep failing. So should I create a separate PR for each package and update and publish one package at a time starting from the bottom of the dependency tree?

[XavierChanth]

static analysis will keep failing. So should I create a separate PR for each package and update and publish one package at a time starting from the bottom of the dependency tree?

There's no need to do all that extra work, we can simply:

Review > Approve > Publish > Retrigger CI > Approve > Merge

[XavierChanth]

Some of the stable checks are still failing.

[CurtlyCritchlow]

Some of the stable checks are still failing.

They will be resolved as I publish the package. These are fixes I already made. When approved I'll double check each package make updates if still needed request approval and publish starting with at_commons_flutter moving up the tree. For packages that are already updated with no stable checks failure I will publish since it would have already passed approval.

[CurtlyCritchlow]

last commit is for at_theme_flutter. forgot to mention the package in the commit message.