Disallow create_function and support PHPStan 1.12.6, getting ready for 2.0

[spaze]

• Add create_function as a disallowed function call (Add create_function as a disallowed function call #261, thanks @BackEndTea)
• Process ClassConstFetch where $class is Name only for enums to correctly support PHPStan 1.12.6 (Process ClassConstFetch where $class is Name only for enums #266)

Internal changes:

• Add phpstan/phpstan-deprecation-rules in expectation of PHPStan 2.0 (Add phpstan/phpstan-deprecation-rules in expectation of PHPStan 2.0 #263)
• Fix test class name (Fix test class name #260, spotted by @szepeviktor, thanks)

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This discussion was created from the release Disallow create_function and support PHPStan 1.12.6, getting ready for 2.0.