Document 3.x as unmaintained (ansible-collections#2212)

SUMMARY
Document that 3.x is unmaintained.
ISSUE TYPE

Docs Pull Request

COMPONENT NAME
README.md
ADDITIONAL INFORMATION

README.md

@@ -9,9 +9,10 @@ The collection includes the VMware modules and plugins supported by Ansible VMwa
 | Release | Status                      | End of life |
 | ------: | --------------------------: | ----------: |
 |       5 | Maintained                  |    Nov 2026 |
-|       4 | Maintained                  |    Nov 2025 |
-|       3 | Maintained (bug fixes only) |    Nov 2024 |
+|       4 | Maintained (bug fixes only) |    Nov 2025 |
+|       3 | Unmaintained                |    Nov 2024 |
 |       2 | Unmaintained                |    Nov 2023 |
+|       1 | Unmaintained                |    Nov 2022 |
 
 ## Ansible version compatibility