Demote Safari to best-effort support

Author: sgravrock

README.md

@@ -30,7 +30,7 @@ Microsoft Edge) as well as Node.
 | Environment | Supported versions |
 |-------------------|----------------------------|
 | Node | 18, 20, 22 |
-| Safari | 15-17  |
+| Safari | 15*, 16*, 17* |
 | Chrome | Evergreen |
 | Firefox | Evergreen, 102*, 115*, 128 |
 | Edge | Evergreen |
@@ -39,9 +39,9 @@ For evergreen browsers, each version of Jasmine is tested against the version of
 at the time of release. Other browsers, as well as older & newer versions of some supported browsers, are likely to work.
 However, Jasmine isn't tested against them and they aren't actively supported. 
 
-\* Environments that are past end of life are supported on a best-effort basis.
-They may be dropped in a future minor release of Jasmine if continued support
-becomes impractical.
+\* Supported on a best-effort basis. Support for these versions may be dropped
+if it becomes impractical, and bugs affecting only these versions may not be
+treated as release blockers.
 
 To find out what environments work with a particular Jasmine release, see the [release notes](https://github.com/jasmine/jasmine/tree/main/release_notes).