interaction.guild.channels.cache is a collection of GuildChannel.

GuildChannels combines all theses categories of channels.

Unfortunately, only Text Channels and News Channels have a messages property.

Maybe you need to check this condition before fetch the messages.

interaction.guild.channels.cache.forEach(c => {
   if(c.type == 'GUILD_TEXT'){
      c.messages.fetch({limit: 10}).then(msgs => {
         msgs.forEach(m => {
            if (m.content.includes(interaction.options.getString('text',true))) {
               // will do stuff here
            }
         }).catch(err => console.error(err))
      })
   }
})

You can also filter the channels

interaction.guild.channels.cache.filter((c) => c.type == 'GUILD_TEXT').forEach(c => {
   c.messages.fetch({limit: 10}).then(msgs => {
      msgs.forEach(m => {
         if (m.content.includes(interaction.options.getString('text',true))) {
            // will do stuff here
         }
      }).catch(err => console.error(err))
   })
})