Update orchestra/canvas requirement from ^4.0||5.0 to ^4.0||5.0||^5.0

Updates the requirements on [orchestra/canvas](https://github.com/orchestral/canvas) to permit the latest version.
- [Release notes](https://github.com/orchestral/canvas/releases)
- [Commits](https://github.com/orchestral/canvas/commits/v5.1.0)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

composer.json

@@ -28,7 +28,7 @@
     },
     "require-dev": {
         "orchestra/testbench": "^4.0||^5.0",
-        "orchestra/canvas": "^4.0||5.0",
+        "orchestra/canvas": "^4.0||5.0||^5.0",
         "phpunit/phpunit": "^8.0"
     },
     "autoload": {