docs: update deprecation status of LCOW to "removed"

[thaJeztah]

Although not all changes have been merged yet, LCOW is no longer functional,
so updating the status to "removed" to reflect this.

List of related pull-requests:

• Remove LCOW (step 1) moby/moby#42451 Remove LCOW (step 1)
• Remove LCOW (step 2) moby/moby#42499 Remove LCOW (step 2)
• Remove LCOW (step 3): daemon: remove graphdriver indexing by OS moby/moby#42506 Remove LCOW (step 3): daemon: remove graphdriver indexing by OS
• Remove LCOW (step 4): remove layerstore indexing by OS (used for LCOW) moby/moby#42511 Remove LCOW (step 4): remove layerstore indexing by OS (used for LCOW)
• Remove LCOW (step 5): volumes/mounts: remove LCOW code (alternative) moby/moby#42520 Remove LCOW (step 5): volumes/mounts: remove LCOW code (alternative)
• Remove LCOW (step 6) moby/moby#42683 Remove LCOW (step 6)
• Remove LCOW (step 7): remove LCOW bits from builder/dockerfile (copy) moby/moby#42684 Remove LCOW (step 7): remove LCOW bits from builder/dockerfile (copy)
• Remove LCOW (step 8): libcontainerd/local: remove LCOW bits moby/moby#42685 Remove LCOW (step 8): libcontainerd/local: remove LCOW bits
• WIP: Remove legacy LCOW code moby/moby#42170 WIP: Remove legacy LCOW code

- What I did

- How I did it

- How to verify it

- Description for the changelog

- A picture of a cute animal (not mandatory but encouraged)

[codecov-commenter]

Codecov Report

Merging #3223 (8916855) into master (c9f8473) will not change coverage.
The diff coverage is n/a.

@@ Coverage Diff @@## master #3223 +/- ##
=======================================
Coverage 58.58% 58.58% =======================================
Files 299 299 Lines 21502 21502 =======================================
Hits 12597 12597 Misses 7983 7983 Partials 922 922 

[thaJeztah]

@silvin-lubecki@StefanScherer ptal

[silvin-lubecki]

LGTM 🎉