[PAINTROID-797] Update to Flutter 3.41.0

[this-is-varunxyz]

This PR upgrades the project from Flutter 3.6.2 to the latest stable version 3.41.0. It addresses major dependency updates, fixes rendering regressions in SVG assets, and optimizes the Android build environment for improved stability and performance.

Jira Ticket: LINK
New Features and Enhancements

Flutter & Dart Upgrade: Migrated the project environment to Flutter 3.41.0 and Dart 3.11.

Dependency Modernization: Updated 119 packages to their latest major versions, including flutter_svg, flutter_riverpod, and floor.

Build Optimization: Updated android/gradle.properties to increase Xmx to 1536M and MaxMetaspaceSize to 512m for better compilation stability.

AndroidX & Jetifier: Confirmed useAndroidX=true and disabled enableJetifier to improve build speeds, as per modern Flutter standards.

Refactorings and Bug Fixes

SVG Rendering Fix: Standardized SVG fill colors (changing non-standard #FF000000 to #000000) to resolve an issue where certain tool icons (Brush, Eraser, Fill) rendered as 0% opaque in the new Flutter engine.

Code Compatibility: Updated IconSvg widget and other UI components to utilize the new ColorFilter and BlendMode APIs required by flutter_svg 2.x.

Checklist

[x] Include the name of the Jira ticket in the PR’s title

[x] Add the link to the ticket in Jira in the description of the PR

[x] Include a summary of the changes plus the relevant context

[x] Choose the proper base branch (develop)

[x] Confirm that the changes follow the project’s coding guidelines (Wiki)

[x] Verify that the changes generate no compiler or linter warnings

[x] Perform a self-review of the changes

[x] Verify to commit no other files than the intentionally changed ones

[x] Include reasonable and readable tests verifying the added or changed behavior

[x] Confirm that new and existing tests pass locally

[x] Check that the commits’ message style matches the [project’s guideline](https://github.com/Catrobat/Catroid/wiki/Commit-Message-Guidelines)

[x] Verify that your changes do not have any conflicts with the base branch

[x] After the PR, verify that all CI checks have passed

[juliajulie95]

Please update the version here too:
https://github.com/Catrobat/Paintroid-Flutter/blob/develop/.github/workflows/main.yml
https://github.com/Catrobat/Paintroid-Flutter/blob/develop/.fvmrc

[this-is-varunxyz]

done

[juliajulie95]

Please verify that these analysis errors do not happen locally: https://github.com/Catrobat/Paintroid-Flutter/actions/runs/22074865183/job/63964889024?pr=147
They might occur because github action always uses the action workflow from develop which still has the olf flutter version