gatsby-remark-images : bug: uses filename as alt text when showCaptions is true

gatsby-remark-images : bug: uses filename as alt text when showCaptions is true: a task in MiMo-V2.6-RL-harbor-code: MiMo-V2.6-RL Code (Harbor) (Harbor dataset). Since https://github.com/gatsbyjs/gatsby/pull/13489, when using showCaptions:true gatsby-remark-images inserts the file name, when using…

The task

Since https://github.com/gatsbyjs/gatsby/pull/13489, when using `showCaptions:true` `gatsby-remark-images` inserts the file name, when using the standard img snippet:

Part of FineEnvs/MiMo-V2.6-RL-harbor-code.