[DOCS]Removes link pointing to EIS reference docs

[szabosteve]

Overview

EIS won't be released in 8.18/9.0. The docs referencing EIS need to be pulled out from the generated docs.
This PR pullso out EIS docs from ES: elastic/elasticsearch#126381
The CI on that PR fails as one of the pages in elasticsearch-js links to the content I want to remove. This PR deletes the link to unblock the PR in the ES repo.

[JoshMock]

Merging as-is, but also updated the code generator to ensure the link doesn't come back.

[github-actions]

The backport to 8.16 failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-8.16 8.16
# Navigate to the new working tree
cd .worktrees/backport-8.16
# Create a new branch
git switch --create backport-2708-to-8.16
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 6042bcd20c4b69b0f92801e3389b34780be844b1
# Push it to GitHub
git push --set-upstream origin backport-2708-to-8.16
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-8.16

Then, create a pull request where the base branch is 8.16 and the compare/head branch is backport-2708-to-8.16.

[github-actions]

The backport to 8.17 failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-8.17 8.17
# Navigate to the new working tree
cd .worktrees/backport-8.17
# Create a new branch
git switch --create backport-2708-to-8.17
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 6042bcd20c4b69b0f92801e3389b34780be844b1
# Push it to GitHub
git push --set-upstream origin backport-2708-to-8.17
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-8.17

Then, create a pull request where the base branch is 8.17 and the compare/head branch is backport-2708-to-8.17.

[github-actions]

The backport to 8.x failed:

The process '/usr/bin/git' failed with exit code 1

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-8.x 8.x
# Navigate to the new working tree
cd .worktrees/backport-8.x
# Create a new branch
git switch --create backport-2708-to-8.x
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 6042bcd20c4b69b0f92801e3389b34780be844b1
# Push it to GitHub
git push --set-upstream origin backport-2708-to-8.x
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-8.x

Then, create a pull request where the base branch is 8.x and the compare/head branch is backport-2708-to-8.x.