[v5] inconcistency in tags for Nether Fortress goals

[rybak]

"Wither Skull" and "Skull Charge Banner Pattern" have tag RareBiome. The rare biome presumably being the Nether Fortress. The following goals, which require a Fortress don't have the tag:

• "Get Regeneration from a Beacon"
• "Blaze Rod"
• potion goals, which require blaze powder (all except fire resistance)
• "Eye of Ender"
• "Finish on top of a Blaze Spawner"
• "(16-32) Red Nether Brick Blocks" requires netherwart, which can be found both in fortresses and in 25% of bastions (the housing unit type)

Should all of them have the tag or none of them? Similar question could be asked about the goal which requires finding a Bastion Remnant – "Give a Piglin Brute an Enchanted Axe".

Maybe this could be part of the SpecificBiome tag addition, which was mentioned in #101.