cli: remove most lockfile analysis features

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

docs/getting-started/keeping-backstage-updated.md

@@ -63,18 +63,16 @@ When a given dependency version is the _same_ between different packages, the
 dependency is hoisted to the main `node_modules` folder in the monorepo root to
 be shared between packages. When _different_ versions of the same dependency are
 encountered, Yarn creates a `node_modules` folder within a particular package.
+This can lead to multiple versions of the same package being installed and used
+in the same app.
 
-This can lead to confusing situations with type definitions, or anything with
-global state. React [Context](https://reactjs.org/docs/context.html), for
-example, depends on global referential equality. This can cause problems in
-Backstage with API lookup, or config loading.
+All Backstage core packages are implemented in such as way that package
+duplication is **not** a problem. For example, duplicate installations of
+packages like `@backstage/core-plugin-api`, `@backstage/core-components`,
+`@backstage/plugin-catalog-react`, and `@backstage/backend-plugin-api` are all
+acceptable.
 
-To help resolve these situations, the Backstage CLI has
-[versions:check](https://backstage.io/docs/tooling/cli/03-commands#versionscheck). This
-will validate versions of `@backstage` packages in your app to check for
-duplicate definitions:
-
-```bash
-# Add --fix to attempt automatic resolution in yarn.lock
-yarn backstage-cli versions:check
-```
+While package duplication might be acceptable in many cases, you might want to
+deduplicate packages for the purpose of optimizing bundle size and installation
+speed. We recommend using deduplication utilities such as `yarn dedupe` to trim
+down the number of duplicate packages.

docs/tooling/cli/03-commands.md

@@ -26,7 +26,6 @@ repo [command]                                 Command that run across an entire
 package [command]                              Lifecycle scripts for individual packages
 migrate [command]                              Migration utilities
 versions:bump [options]                        Bump Backstage packages to the latest versions
-versions:check [options]                       Check Backstage package versioning
 clean                                          Delete cache directories [DEPRECATED]
 build-workspace <workspace-dir> [packages...]  Builds a temporary dist workspace from the provided
                                                 packages
@@ -327,8 +326,7 @@ Options:
 ## versions\:bump
 
 Bump all `@backstage` packages to the latest versions. This checks for updates
-in the package registry, and will update entries both in `yarn.lock` and
-`package.json` files when necessary.
+in the package registry, and will update entries `package.json` files when necessary.
 
 ```text
 Usage: backstage-cli versions:bump [options]
@@ -339,23 +337,6 @@ Options:
   --release <version|next|main> Bump to a specific Backstage release line or version (default: "main")
 ```
 
-## versions\:check
-
-Validate `@backstage` dependencies within the repo, making sure that there are
-no duplicates of packages that might lead to breakages.
-
-By supplying the `--fix` flag the command will attempt to fix any conflict that
-can be resolved by editing `yarn.lock`, but will not attempt to search for
-remote updates or modify any `package.json` files.
-
-```text
-Usage: backstage-cli versions:check [options]
-
-Options:
-  --fix       Fix any auto-fixable versioning problems
-  -h, --help  display help for command
-```
-
 ## build-workspace
 
 Builds a mirror of the workspace using the packaged production version of each