Merge pull request #981 from gchq/fix/rtd-images

ci(docs): fix LFS in ReadTheDocs build

.readthedocs.yaml

@@ -9,6 +9,24 @@ build:
     # Note that we use 3.12 here rather than 3.13 to avoid spurious Sphinx errors
     # about not being able to link to `pathlib._locals.Path`.
     python: "3.12"
+  jobs:
+    # Fix LFS images. See documentation at:
+    # https://docs.readthedocs.com/platform/stable/build-customization.html#support-git-lfs-large-file-storage
+    post_checkout:
+      # Download and uncompress the binary
+      # https://git-lfs.github.com/
+      - wget https://github.com/git-lfs/git-lfs/releases/download/v3.6.1/git-lfs-linux-amd64-v3.6.1.tar.gz
+      - tar xvfz git-lfs-linux-amd64-v3.6.1.tar.gz  # cspell:disable-line
+      # Modify LFS config paths to point where git-lfs binary was downloaded
+      - git config filter.lfs.process "`pwd`/git-lfs-3.6.1/git-lfs filter-process"
+      - git config filter.lfs.smudge  "`pwd`/git-lfs-3.6.1/git-lfs smudge -- %f"
+      - git config filter.lfs.clean "`pwd`/git-lfs-3.6.1/git-lfs clean -- %f"
+      # Make LFS available in current repository
+      - ./git-lfs-3.6.1/git-lfs install
+      # Download content from remote
+      - ./git-lfs-3.6.1/git-lfs fetch
+      # Make local files to have the real content on them
+      - ./git-lfs-3.6.1/git-lfs checkout
 
 sphinx:
   configuration: documentation/source/conf.py