fix: calculate error suppression per snapshot

[Kha]

Generalizes #3556 to not suppressing errors in tactic steps either when the parse error is in a later step, as otherwise changes to the end of a proof would affect (correctness or effectiveness of) incrementality of preceding steps.

Fixes #4623, in combination with #4643

[leanprover-community-mathlib4-bot]

Mathlib CI status (docs):

• ❗ Batteries CI can not be attempted yet, as the nightly-testing-2024-07-05 tag does not exist there yet. We will retry when you push more commits. If you rebase your branch onto nightly-with-mathlib, Batteries CI should run now. (2024-07-05 08:49:58)

[github-actions]

The backport to releases/v4.9.0 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-releases/v4.9.0 releases/v4.9.0
# Navigate to the new working tree
cd .worktrees/backport-releases/v4.9.0
# Create a new branch
git switch --create backport-4657-to-releases/v4.9.0
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 4d2f2d7cc59f1df0417f7b58329cbd3fbd2f0906
# Push it to GitHub
git push --set-upstream origin backport-4657-to-releases/v4.9.0
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-releases/v4.9.0

Then, create a pull request where the base branch is releases/v4.9.0 and the compare/head branch is backport-4657-to-releases/v4.9.0.

[github-actions]

The backport to releases/v4.10.0 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-releases/v4.10.0 releases/v4.10.0
# Navigate to the new working tree
cd .worktrees/backport-releases/v4.10.0
# Create a new branch
git switch --create backport-4657-to-releases/v4.10.0
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick -x --mainline 1 4d2f2d7cc59f1df0417f7b58329cbd3fbd2f0906
# Push it to GitHub
git push --set-upstream origin backport-4657-to-releases/v4.10.0
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-releases/v4.10.0

Then, create a pull request where the base branch is releases/v4.10.0 and the compare/head branch is backport-4657-to-releases/v4.10.0.