Bump SDK version using in CI to 3.3

Mockito now requires Dart SDK 3.3, so bump the SDK version used in CI.

Author: Ilya Yanok

.github/workflows/test-package.yml

@@ -24,7 +24,7 @@ jobs:
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11
       - uses: dart-lang/setup-dart@fedb1266e91cf51be2fdb382869461a434b920a3
         with:
-          sdk: 3.1.0
+          sdk: 3.3.0
       - id: install
         name: Install dependencies
         run: dart pub get
@@ -37,7 +37,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        sdk: [3.1.0, dev]
+        sdk: [3.3.0, dev]
     steps:
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11
       - uses: dart-lang/setup-dart@fedb1266e91cf51be2fdb382869461a434b920a3
@@ -59,7 +59,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest]
-        sdk: [3.1.0, dev]
+        sdk: [3.3.0, dev]
     steps:
       - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11
       - uses: dart-lang/setup-dart@fedb1266e91cf51be2fdb382869461a434b920a3