Bump Maestro CI version to 2.6.1 for rn-tester e2e (#57307)

Summary:
Pull Request resolved: https://github.com/react/react-native/pull/57307

Bumps `MAESTRO_VERSION` from `1.40.0` to `2.6.1` so we can use the new the visual-regression `assertScreenshot` command.

The two Maestro 2.0.0 breaking changes are already satisfied: JDK 17 is set up in both actions (`actions/setup-java@v5`), and the flows use only plain `${...}` variable interpolation rather than the JS scripting affected by the Rhino -> GraalJS engine swap.

Changelog: [Internal]

Reviewed By: christophpurrer

Differential Revision: D109359976

fbshipit-source-id: 78377a8dadaaee5d316513adc47d56a2b9b4dc40

.github/actions/maestro-android/action.yml

@@ -32,7 +32,7 @@ runs:
   steps:
     - name: Installing Maestro
       shell: bash
-      run: export MAESTRO_VERSION=1.40.0; curl -Ls "https://get.maestro.mobile.dev" | bash
+      run: export MAESTRO_VERSION=2.6.1; curl -Ls "https://get.maestro.mobile.dev" | bash
     - name: Set up JDK 17
       if: ${{ inputs.install-java == 'true' }}
       uses: actions/setup-java@v5

.github/actions/maestro-ios/action.yml

@@ -24,7 +24,7 @@ runs:
   steps:
     - name: Installing Maestro
       shell: bash
-      run: export MAESTRO_VERSION=1.40.0; curl -Ls "https://get.maestro.mobile.dev" | bash
+      run: export MAESTRO_VERSION=2.6.1; curl -Ls "https://get.maestro.mobile.dev" | bash
     - name: Installing Maestro dependencies
       shell: bash
       run: |