Upsert to stage 3, per 2025.07.28 TC39

ljharb · ljharb · commit a9c0dfa4e00f · 2025-07-28T16:16:46.000-07:00
diff --git a/README.md b/README.md
@@ -33,6 +33,7 @@ Stage 2 indicates that the committee expects these features to be developed and
 | [`Atomics.pause`][atomics-pause]                                               | Shu-yu Guo                                                              | Shu-yu Guo                                                              | <sub>[Atomics.pause][atomics-pause-tests]</sub>                     | <sub>[October&nbsp;2024][atomics-pause-notes]</sub>        |
 | [Deferring Module Evaluation][lazy-import]                                     | Yulia Startsev<br />Guy Bedford                                         | Yulia Startsev<br />Guy Bedford<br />Nicol&ograve; Ribaudo                     | <sub>[Testing plan][lazy-import-testplan]</sub>                     | <sub>[February&nbsp;2025][lazy-import-notes]</sub>         |
 | [Iterator Sequencing][sequencing]                                              | Michael Ficarra                                                         | Michael Ficarra                                                         | :question:                                                          | <sub>July&nbsp;2025</sub>                                  |
+| [`Upsert`][upsert]                                                             | Daniel Minor, Lauritz Thoresen Angeltveit, Jonas Haukenes, Sune Lianes, Vetle Larsen, Mathias Hop Ness | Daniel Minor                             | <sub>[Testing plan][upsert-testing-plan]</sub>                      | <sub>July&nbsp;2025</sub>                                  |
 
 
 ### Stage 2.7
@@ -44,7 +45,6 @@ Stage 2 indicates that the committee expects these features to be developed and
 | [ESM Phase Imports][esm-phase]                                                 | Luca Casonato<br />Guy Bedford                                          | Luca Casonato<br />Guy Bedford                                          | :question:                                                          | <sub>[December&nbsp;2024][esm-phase-notes]</sub>           |
 | [Immutable ArrayBuffers][immutable-abs]                                        | Mark Miller<br />Peter Hoddie<br />Richard Gibson<br />Jack Works | Mark Miller<br />Peter Hoddie<br />Richard Gibson<br />Jack Works             | :question:                                                          | <sub>[February&nbsp;2025][immutable-abs-notes]</sub>       |
 | [Non-extensible Applies to Private][nonext-private]                            | Mark Miller<br />Shu-yu Guo<br />Chip Morningstar<br />Erik Marks | Mark Miller<br />Shu-yu Guo<br />Chip Morningstar<br />Erik Marks             | :question:                                                          | <sub>[April&nbsp;2025][nonext-private-notes]</sub>                                |
-| [`Upsert`][upsert]                                                             | Daniel Minor, Lauritz Thoresen Angeltveit, Jonas Haukenes, Sune Lianes, Vetle Larsen, Mathias Hop Ness | Daniel Minor                             | <sub>[Testing plan][upsert-testing-plan]</sub>                      | <sub>[April&nbsp;2025][upsert-notes]</sub>                                |
 
 
 ### Stage 2
