Fire is invisible when lit on glass blocks

[TobiasGrether]

Issue description

• Expected result: What were you expecting to happen?
• Fire should be visible on glass blocks, although I am unsure whether it should be able to burn on glass anyways. (Possibly related to #3719)
• Actual result: What actually happened? Glass is lit on fire, but the fire is invisible to players.

  Steps to reproduce the issue

  1. Place glass
  2. Lit glass on fire using flint & steel

OS and versions

• PocketMine-MP: 4.2.2+dev
• PHP: 8.0.16
• Using JIT: no
• Server OS: MacOS
• Game version: MacOS

Plugins

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• If you remove all plugins, does the issue still occur?
• Yes

Crashdump, backtrace or other files

[dktapps]

related to #4856

[dktapps]

correction: this has nothing to do with #4856 whatsoever; the problem remains that transparent non-flammable blocks shouldn't get fire placed on them. Mixing up isSolid and !isTransparent seems to be a common source of gameplay bugs.