meta: clarify EoL platform support

PR-URL: #25838
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>

BUILDING.md

@@ -69,9 +69,12 @@ There are three support tiers:
 
 ### Supported platforms
 
-The community does not build or test against end-of-life distributions (EoL).
 For production applications, run Node.js on supported platforms only.
 
+Node.js does not support a platform version if a vendor has expired support
+for it. In other words, Node.js does not support running on End-of-life (EoL)
+platforms. This is true regardless of entries in the table below.
+
 | System       | Support type | Version                         | Architectures    | Notes                         |
 | ------------ | ------------ | ------------------------------- | ---------------- | ----------------------------- |
 | GNU/Linux    | Tier 1       | kernel >= 2.6.32, glibc >= 2.12 | x64, arm         |                               |