THRIFT-5977: Apply constructor property promotion in PHP runtime library

[sveneld]

Summary

Follow-up to THRIFT-5976 (typed properties). After that work, many constructors in lib/php/lib/ were pure 1:1 argument→property assignments — exactly what PHP 8 constructor property promotion replaces. Apply promotion across the library: cleaner declarations, no behavioural change, no LSP impact.

JIRA: https://issues.apache.org/jira/browse/THRIFT-5977 (related to THRIFT-5960).

Scope

Full promote (ctor body becomes empty or a single parent call)

• Factory/TBinaryProtocolFactory — strictRead, strictWrite.
• Server/TServer (6 properties) — processor, transport, four factory parameters.
• Server/TServerSocket — host, port (acceptTimeout retained as a regular property, mutated via setAcceptTimeout()).
• Transport/TMemoryBuffer — buf.
• Transport/TBufferedTransport — transport, rBufSize, wBufSize.
• Transport/TFramedTransport — transport, read, write.
• ClassLoader/ThriftClassLoader — apcu, apcu_prefix.

Partial promote (body keeps parent::__construct(...) or one non-trivial line)

• Protocol/TBinaryProtocol — strictRead, strictWrite; $trans forwarded to parent.
• Protocol/TMultiplexedProtocol — serviceName; $protocol forwarded.
• StoredMessageProtocol — fname, mtype, rseqid; $protocol forwarded.
• Transport/TSocket — host, port, persist; debugHandler retains the ?: 'error_log' fallback in the body.
• Transport/THttpClient — host, port, scheme, context; uri keeps its prefix-normalisation in the body.
• Transport/TCurlClient — host, port, scheme; same uri logic.

Bonus fixes surfaced while promoting

• Transport/TSSLSocket was bypassing parent::__construct entirely. Now properly delegates parent::__construct(self::getSSLHost($host), $port, false, $debugHandler), ensuring TSocket's promoted properties get initialised. getSSLHost made private static since it doesn't use $this.
• Server/TSSLServerSocket — same pattern: parent::__construct(self::getSSLHost($host), $port); getSSLHost made public static.

Out of scope (intentionally skipped)

• TPhpStream — bitwise ($mode & MODE_R/MODE_W) ctor logic, not 1:1.
• Exception hierarchy (TException, TApplicationException, TProtocolException, TTransportException) — dual-mode bridge constructor.
• TBase, TSimpleJSONProtocol, TJSONProtocol — non-trivial init bodies ($context = new Context(), $reader = new LookaheadReader(), conditional spec/vals processing).
• TSocketPool — ctor builds $servers and normalises $ports; not 1:1.
• TBinaryProtocolAccelerated — passes through to parent unchanged after the parent promotion.

Verification (PHP 8.4 / composer 2 / phpstan 1.12 / phpunit 13 in docker)

composer phpstan         OK (level 1, baseline unchanged)
vendor/bin/phpcs         OK
phpunit Unit suite       629 tests, 1907 assertions, 0 errors
phpunit Integration      106 tests,  166 assertions, 0 errors

Checklist

• Did you create an Apache Jira ticket? — THRIFT-5977
• If a ticket exists: Does your pull request title follow the pattern "THRIFT-NNNN: describe my issue"?
• Did you squash your changes to a single commit?
• Did you do your best to avoid breaking changes? — yes; promotion is purely syntactic. The only observable diff is that TSSLSocket and TSSLServerSocket now correctly call parent::__construct, which initialises previously-uninitialised inherited typed properties (no functional behaviour change for callers since the SSL classes overrode every method that read those properties).
• If your change does not involve any code, include [skip ci] anywhere in the commit message to free up build resources.