Avoid explicit line break in README

Author: eregon

README.md

@@ -14,7 +14,7 @@ This action currently supports these versions of MRI, JRuby and TruffleRuby:
 
 | Interpreter | Versions |
 | ----------- | -------- |
-| `ruby` | 2.1.9, 2.2, 2.3.0 - 2.3.8, 2.4.0 - 2.4.10, 2.5.0 - 2.5.8, 2.6.0 - 2.6.6, 2.7.2, 3.0.0,<br/> head, debug, mingw, mswin |
+| `ruby` | 2.1.9, 2.2, 2.3.0 - 2.3.8, 2.4.0 - 2.4.10, 2.5.0 - 2.5.8, 2.6.0 - 2.6.6, 2.7.2, 3.0.0, head, debug, mingw, mswin |
 | `jruby` | 9.1.17.0, 9.2.9.0 - 9.2.13.0, head |
 | `truffleruby` | 19.3.0 - 20.3.0, head |