chore: deprecate Ordinal.blsub

[vihdzp]

In favor of simply writing ⨆ i : Iio a, f i + 1. See #17033.

---

• depends on: chore(SetTheory/Cardinal/Cofinality): deprecate many lemmas on lsub/blsub #36940
• depends on: [Merged by Bors] - feat(SetTheory/Ordinal): fundamental sequences #37019

[github-actions]

PR summary 56a14629eb

Import changes for modified files

No significant changes to the import graph

Import changes for all files

Files	Import difference

---

Declarations diff

+ aleph_one_le_iff
+ cof_omega_one
+ lift_eq_omega_one
+ lift_le_omega_one
+ lift_lt_omega_one
+ lt_aleph_one_iff
+ omega_one_eq_lift
+ omega_one_le_lift
+ omega_one_lt_lift

You can run this locally as follows

## summary with just the declaration names:
./scripts/pr_summary/declarations_diff.sh <optional_commit>

## more verbose report:
./scripts/pr_summary/declarations_diff.sh long <optional_commit>

The doc-module for scripts/pr_summary/declarations_diff.sh contains some details about this script.

---

Increase in tech debt: (relative, absolute) = (1.00, 0.08)

Current number	Change	Type
13	1	disabled deprecation lints

Current commit ceac426946
Reference commit 56a14629eb

You can run this locally as

./scripts/reporting/technical-debt-metrics.sh pr_summary

• The relative value is the weighted sum of the differences with weight given by the inverse of the current value of the statistic.
• The absolute value is the relative value divided by the total sum of the inverses of the current values (i.e. the weighted average of the differences).

[mathlib-dependent-issues]

This PR/issue depends on:

• chore(SetTheory/Cardinal/Cofinality): deprecate many lemmas on lsub/blsub #36940
• [Merged by Bors] - feat(SetTheory/Ordinal): fundamental sequences #37019
  By Dependent Issues (🤖). Happy coding!