PHP 8.5 support

[maksimovic]

Hello. I'm preparing a project for upgrade to PHP 8.5, but couldn't install pubnub/php. Investigating lead to some changes, which I'm proposing here:

CI:

• Add 8.5 to the test matrix

Installation:

• Drop the committed composer.lock. The locked behat 3.19 / gherkin 4.12 declare php 8.1.* || 8.2.* || 8.3.* || 8.4.* and refuse to install on 8.5, even though composer.json (php >=8.1) permits it. Resolving fresh from composer.json on 8.5 picks compatible point releases within the same constraints.

src/ deprecation fixes:

• PaddingTrait::depad() and PubNubCryptoCore::unPadPKCS7() both wrap a string-comparison boolean in ord() which feels like a bug, which surfaced now that passing an empty string to ord() is deprecated (false coerces to "")
• CryptoModule::decodeHeader() guard "strlen(header < 10)" applies strlen() to the boolean of $header < 10, returning 0 or 1, so it never actually checks header length

Tests:

• Remove ReflectionMethod::setAccessible(true) calls in tests (deprecated in 8.5, and in fact a no-op since 8.1 anyway).

In fact, the library seems to be in a pretty good shape, but the composer.lock is the first and biggest problem. Its constraints propagate to projects using it, which can have undesired consequences or, like in this case, outright inability to even install it. I see that it's tracked for quite a long time (since v3?), without reasons explaining the tracking.

[pubnub-ops-terraform]

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