Revert: Only expose used CSS variables (#16403)

This reverts #16211

We found some unexpected interactions with using `@apply` and CSS
variables in multi-root setups like CSS modules or Vue inline `<style>`
blocks that were broken due to that change. We plan to re-enable this
soon and include a proper fix for those scenarios.

## Test plan

- Updated snapshots
- Tested using the CLI in a new project:
<img width="1523" alt="Screenshot 2025-02-10 at 13 08 42"
src="https://github.com/user-attachments/assets/defe0858-adb3-4d61-9d2c-87166558fd68"
/>

---------

Co-authored-by: Robin Malfait <[email protected]>

Author: philipp-spiess

Diff for: .github/workflows/prepare-release.yml

@@ -264,6 +264,8 @@ jobs:
 
       - name: Build Tailwind CSS
         run: pnpm run build
+        env:
+          FEATURES_ENV: stable
 
       - name: Run pre-publish optimizations scripts
         run: node ./scripts/pre-publish-optimizations.mjs

Diff for: .github/workflows/release.yml

@@ -256,6 +256,8 @@ jobs:
 
       - name: Build Tailwind CSS
         run: pnpm run build
+        env:
+          FEATURES_ENV: stable
 
       - name: Run pre-publish optimizations scripts
         run: node ./scripts/pre-publish-optimizations.mjs

Diff for: CHANGELOG.md

@@ -7,7 +7,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-Nothing yet!
+### Fixed
+
+- Revert change to no longer include theme variables that aren't used in compiled CSS
 
 ## [4.0.5] - 2025-02-08
 

Diff for: integrations/cli/index.test.ts

@@ -1289,7 +1289,9 @@ test(
     expect(await fs.dumpFiles('./dist/*.css')).toMatchInlineSnapshot(`
       "
       --- ./dist/out.css ---
-      <EMPTY>
+      :root, :host {
+        --color-blue-500: blue;
+      }
       "
     `)
 

Diff for: packages/@tailwindcss-postcss/src/__snapshots__/index.test.ts.snap

@@ -330,7 +330,11 @@ test('runs `Once` plugins in the right order', async () => {
   )
 
   expect(result.css.trim()).toMatchInlineSnapshot(`
-    ".custom-css {
+    ":root, :host {
+      --color-red-500: red;
+    }
+
+    .custom-css {
       color: red;
     }"
   `)
@@ -343,7 +347,11 @@ test('runs `Once` plugins in the right order', async () => {
     }"
   `)
   expect(after).toMatchInlineSnapshot(`
-    ".custom-css {
+    ":root, :host {
+      --color-red-500: red;
+    }
+
+    .custom-css {
       color: red;
     }"
   `)