ci(php): Use PHP 8.4 for linting

[ptondereau]

Description

Checklist

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• I have read the contribution guidelines.
• I have added tests that prove my code works as expected.
• I have added documentation if applicable.
• I have added a migration guide if applicable.

❤️ Thank you for your contribution!

[coveralls]

Pull Request Test Coverage Report for Build 18845248028

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 101 unchanged lines in 13 files lost coverage.
• Overall coverage increased (+3.4%) to 31.121%

---

Files with Coverage Reduction	New Missed Lines	%
crates/macros/src/fastcall.rs	1	0.0%
src/types/iterator.rs	1	69.81%
crates/macros/src/extern_.rs	2	0.0%
crates/macros/src/module.rs	2	0.0%
src/types/object.rs	2	11.54%
src/zend/_type.rs	3	64.29%
crates/macros/src/syn_ext.rs	5	0.0%
crates/macros/src/lib.rs	6	15.07%
src/zend/class.rs	7	30.0%
crates/macros/src/impl_.rs	9	0.0%

Totals
Change from base Build 18747498499:	3.4%
Covered Lines:	1355
Relevant Lines:	4354

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 18845244768

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 101 unchanged lines in 13 files lost coverage.
• Overall coverage increased (+3.4%) to 31.121%

---

Files with Coverage Reduction	New Missed Lines	%
crates/macros/src/fastcall.rs	1	0.0%
src/types/iterator.rs	1	69.81%
crates/macros/src/extern_.rs	2	0.0%
crates/macros/src/module.rs	2	0.0%
src/types/object.rs	2	11.54%
src/zend/_type.rs	3	64.29%
crates/macros/src/syn_ext.rs	5	0.0%
crates/macros/src/lib.rs	6	15.07%
src/zend/class.rs	7	30.0%
crates/macros/src/impl_.rs	9	0.0%

Totals
Change from base Build 18747498499:	3.4%
Covered Lines:	1355
Relevant Lines:	4354

---

💛 - Coveralls