Update phpstan/phpstan requirement from ^0.12 to ^1.6

[dependabot[bot]]

Updates the requirements on phpstan/phpstan to permit the latest version.

Release notes

Sourced from phpstan/phpstan's releases.

1.6.1

Bugfixes 🐛

• Be more resilient against non-existent traits and interfaces (https://github.com/ondrejmirtes/BetterReflection/commit/72bb30507092beca32ed3ab021a0de1f685bbd54), #7112
• Fix BackedEnum::from() and tryFrom() methods (https://github.com/phpstan/phpstan-src/commit/e97439c5987fc7747b68d3617a128fad68102642), #7096
• ConditionalReturnTypeRuleHelper - increase type description verbosity (https://github.com/phpstan/phpstan-src/commit/2f49187491aa034d37d2728deb4ee8f5e1102aa6), #7111
• Fix ConstantArrayType for optional/non-optional keys (#1249), #7111, thanks @​rvanvelzen!
• AutoloadSourceLocator - store the first included file (https://github.com/phpstan/phpstan-src/commit/63ef0a9eb76cb25e85ff1966c2011dd4c5d1892a), #7113
• Fix array_push / array_unshift with unpacked non-constant array types (#1247), #7115, thanks @​herndlm!

Commits

• e885276 PHPStan 1.6.1
• a9efdf3 Updated PHPStan to commit 9e27a1775db4d487e31126326eb895431ace5622
• 17f36ab Updated PHPStan to commit 2f49187491aa034d37d2728deb4ee8f5e1102aa6
• 5a8fb50 Swiftmailer bug reproduction
• 75ed05e Updated PHPStan to commit e97439c5987fc7747b68d3617a128fad68102642
• 17b309a Reproduce issue with symfony/event-dispatcher-contracts
• c386374 Updated PHPStan to commit ae35752e264697d1c287746ec1f66691027d492e
• 96488af add documentation for checkDynamicProperties
• 8a65968 Add documentation for global constants
• 7525b53 Update phpdoc-types.md
• Additional commits viewable in compare view

Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting @dependabot rebase.

---

Dependabot commands and options

You can trigger Dependabot actions by commenting on this PR: - `@dependabot rebase` will rebase this PR - `@dependabot recreate` will recreate this PR, overwriting any edits that have been made to it - `@dependabot merge` will merge this PR after your CI passes on it - `@dependabot squash and merge` will squash and merge this PR after your CI passes on it - `@dependabot cancel merge` will cancel a previously requested merge and block automerging - `@dependabot reopen` will reopen this PR if it is closed - `@dependabot close` will close this PR and stop Dependabot recreating it. You can achieve the same result by closing it manually - `@dependabot ignore this major version` will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this minor version` will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this dependency` will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)

[dependabot[bot]]

Superseded by #19.