[docs] Fix outdated SECURITY.md page (#14128)

Author: oliviertassinari

SECURITY.md

@@ -4,11 +4,12 @@
 
 The versions of the project that are currently supported with security updates.
 
-| Version | Supported          |
-| ------: | :----------------- |
-|     6.x | :white_check_mark: |
-|     5.x | :white_check_mark: |
-|   < 5.0 | :x:                |
+| MUI X version | Release    | Supported                            |
+| ------------: | :--------- | :----------------------------------- |
+|        ^7.0.0 | 2024-03-23 | :white_check_mark: Stable major      |
+|        ^6.0.0 | 2023-03-03 | :white_check_mark: Long-term support |
+|        ^5.0.0 | 2021-11-23 | :x:                                  |
+|        ^4.0.0 | 2021-09-28 | :x:                                  |
 
 ## Reporting a vulnerability
 

docs/data/introduction/support/support.md

@@ -94,13 +94,12 @@ This includes issues introduced by external sources, like browser upgrades or ch
 
 ### Supported versions
 
-- MUI X v7: ✅ Stable major (Continuous support).
-- MUI X v6: ⚠️ Long-term support (Guaranteed Support for security issues and regressions).
-- MUI X v5: 🅧 No longer supported.
-- MUI X v4: 🅧 No longer supported.
-- MUI X v3: 🅧 Never existed.
-- MUI X v2: 🅧 Never existed.
-- MUI X v1: 🅧 Never existed.
+| MUI X version | Release    | Supported                                                           |
+| ------------: | :--------- | :------------------------------------------------------------------ |
+|        ^7.0.0 | 2024-03-23 | ✅ Stable major (Continuous support)                                |
+|        ^6.0.0 | 2023-03-03 | ⚠️ Long-term support (Support for security issues and regressions). |
+|        ^5.0.0 | 2021-11-23 | ❌                                                                  |
+|        ^4.0.0 | 2021-09-28 | ❌                                                                  |
 
 ## Community