[DOCS] Remove instances of added in 0.0.0 (+ unrelated randomness)

[leemthompo]

Closes elastic/docs-content#2582

• removes since=0.0.0 from Snapshot* endpoints (all other instances in the repo are in test files)
• some random other changes tagged along

[github-actions]

Following you can find the validation changes against the target branch for the APIs.

No changes detected.

You can validate these APIs yourself by using the make validate target.

[pquentin]

Thanks! LGTM.

[github-actions]

The backport to 9.0 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-9.0 9.0
# Navigate to the new working tree
cd .worktrees/backport-9.0
# Create a new branch
git switch --create backport-5147-to-9.0
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 4401b0b5538f0884407a80d24fa76bbb7364fb86
# Push it to GitHub
git push --set-upstream origin backport-5147-to-9.0
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-9.0

Then, create a pull request where the base branch is 9.0 and the compare/head branch is backport-5147-to-9.0.

[github-actions]

The backport to 9.1 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-9.1 9.1
# Navigate to the new working tree
cd .worktrees/backport-9.1
# Create a new branch
git switch --create backport-5147-to-9.1
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 4401b0b5538f0884407a80d24fa76bbb7364fb86
# Push it to GitHub
git push --set-upstream origin backport-5147-to-9.1
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-9.1

Then, create a pull request where the base branch is 9.1 and the compare/head branch is backport-5147-to-9.1.