Add GHC 9.12.4

Author: sol

.github/workflows/selftest.macos-13.yml

@@ -82,4 +82,5 @@ jobs:
           - 9.10.3
           - 9.12.1
           - 9.12.2
+          - 9.12.4
           - 9.14.1

.github/workflows/selftest.macos-14.yml

@@ -52,4 +52,5 @@ jobs:
           - 9.10.3
           - 9.12.1
           - 9.12.2
+          - 9.12.4
           - 9.14.1

.github/workflows/selftest.macos-15.yml

@@ -52,4 +52,5 @@ jobs:
           - 9.10.3
           - 9.12.1
           - 9.12.2
+          - 9.12.4
           - 9.14.1

.github/workflows/selftest.ubuntu-22.04.yml

@@ -81,4 +81,5 @@ jobs:
           - 9.10.3
           - 9.12.1
           - 9.12.2
+          - 9.12.4
           - 9.14.1

.github/workflows/selftest.ubuntu-24.04.yml

@@ -79,4 +79,5 @@ jobs:
           - 9.10.3
           - 9.12.1
           - 9.12.2
+          - 9.12.4
           - 9.14.1

.github/workflows/selftest.windows-2022.yml

@@ -81,4 +81,5 @@ jobs:
           - 9.10.3
           - 9.12.1
           - 9.12.2
+          - 9.12.4
           - 9.14.1

.github/workflows/selftest.windows-2025.yml

@@ -81,4 +81,5 @@ jobs:
           - 9.10.3
           - 9.12.1
           - 9.12.2
+          - 9.12.4
           - 9.14.1

README.md

@@ -1,7 +1,8 @@
 |                          | `ubuntu-22.04` | `ubuntu-24.04` | `macos-13` | `macos-14` | `macos-15` | `windows-2022` | `windows-2025` |
 | :----------------------- | :------------: | :------------: | :--------: | :--------: | :--------: | :------------: | :------------: |
 | `latest` `9.14` `9.14.1` |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
-| `9.12` `9.12.2`          |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `9.12` `9.12.4`          |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
+| `9.12.2`                 |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
 | `9.12.1`                 |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
 | `9.10` `9.10.3`          |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |
 | `9.10.2`                 |       🟢       |       🟢       |     🟢     |     🟢     |     🟢     |       🟢       |       🟢       |