[Database] Change npc_types walkspeed to be of type float

[Akkadius]

Description

This is a minor change where this makes schema more consistent across projects. Walkspeed is a barely used field.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

Testing

 World |    Info    | CheckVersionsUpToDate ---------------------------------------------------------------------- 
 World |    Info    | CheckVersionsUpToDate   Server | database [9286] binary [9287] checking updates 
 World |    Info    | CheckVersionsUpToDate   Config | [server.auto_database_updates] [true] 
 World |    Info    | CheckVersionsUpToDate ---------------------------------------------------------------------- 
 World |    Info    | UpdateManifest [9287]  [missing] | [2024_11_26_bazaar_find_trader.sql] 
 World |    Info    | UpdateManifest ---------------------------------------------------------------------- 
 World |    Info    | UpdateManifest Automatically backing up database before applying updates 
 World |    Info    | UpdateManifest ---------------------------------------------------------------------- 
 World |    Info    | DatabaseDump MySQL installed [mysql  Ver 15.1 Distrib 10.11.6-MariaDB, for debian-linux-gnu (x86_64) using  EditLine wrapper] 
 World |    Info    | DatabaseDump Database [peq] Host [mariadb] Username [eqemu] 
 World |    Info    | DatabaseDump Backing up database [mysqldump --defaults-extra-file=login.my.cnf peq --allow-keywords --extended-insert --max-allowed-packet=1G --net-buffer-length=32704 --skip-lock-tables   > backups/peq-2025-01-06.sql] 
 World |    Info    | DatabaseDump This can take a few minutes depending on the size of your database 
 World |    Info    | DatabaseDump LOADING... PLEASE WAIT... 
 World |    Info    | DatabaseDump Database dump created at [backups/peq-2025-01-06.sql] 
 World |    Info    | DatabaseDump Compression requested. Compressing dump [backups/peq-2025-01-06.sql] 
 World |    Info    | DatabaseDump Compressed dump created at [backups/peq-2025-01-06.tar.gz] 
 World |    Info    | UpdateManifest ---------------------------------------------------------------------- 
 World |    Info    | UpdateManifest Running database migrations. Please wait... 
 World |    Info    | UpdateManifest ---------------------------------------------------------------------- 
 World |    Info    | UpdateManifest [9287] [2024_11_26_bazaar_find_trader.sql] [ok] 
 World |    Info    | UpdateManifest ---------------------------------------------------------------------- 
 World |    Info    | CheckDbUpdates Updates ran successfully, setting database version to [9287] from [9286] 
 World |    Info    | DatabaseLoadRoutines Loading variables 

Checklist

• I have tested my changes
• I have performed a self-review of my code. Ensuring variables, functions and methods are named in a human-readable way, comments are added only where naming of variables, functions and methods can't give enough context.
• I own the changes of my code and take responsibility for the potential issues that occur
• If my changes make database schema changes, I have tested the changes on a local database (attach image). Updated version.h CURRENT_BINARY_DATABASE_VERSION to the new version. (Delete this if not applicable)