Update nette/tester requirement from 2.6.0 to 2.6.1

[dependabot]

Updates the requirements on nette/tester to permit the latest version.

Release notes

Sourced from nette/tester's releases.

Released version 2.6.1

• PhpInterpreter now passes the command to proc_open() as an array, so PHP handles argument escaping itself and the subshell is bypassed on Linux too – fewer surprises with paths and arguments containing spaces or special characters
• Test::getResult() throws a LogicException instead of silently returning an unset value when the test hasn't finished running yet – mistakes surface immediately rather than turning into puzzling downstream errors
• Improved PHPDoc types and descriptions throughout the framework for better IDE hints and static analysis

Commits

• 86e4d80 Released version 2.6.1
• a93da9b PhpInterpreter: pass command to proc_open() as array
• 8010162 updated ncs.xml
• 18c24c4 updated github actions
• 3cae927 fixed PHPStan errors
• 32c4b90 throw exception in Test::getResult() when result not yet set
• 249d122 improved PHPDoc descriptions
• 1d96669 improved phpDoc types
• b081f2e fixed tests
• 955782a cs
• Additional commits viewable in compare view

[coveralls]

Coverage is 95.238% — dependabot/composer/nette/tester-2.6.1 into master. No base build found for master.