build: Upgrade to macOS 15 due to GitHub Actions deprecation

.github/workflows/build.yml

@@ -380,7 +380,7 @@ jobs:
 
   # MacOS build
   macos-x86:
-    runs-on: macos-13
+    runs-on: macos-15-intel
 
     permissions:
       id-token: write
@@ -397,7 +397,7 @@ jobs:
             name_suffix: ""
             custom_glfw: false
 
-    name: 🍎 macOS 13 x86_64 ${{ matrix.name_suffix }}
+    name: 🍎 macOS 15 x86_64 ${{ matrix.name_suffix }}
 
     steps:
     - name: 🧰 Checkout
@@ -546,7 +546,7 @@ jobs:
 
   macos-arm64:
     runs-on: ubuntu-24.04
-    name: 🍎 macOS 13 arm64
+    name: 🍎 macOS 15 arm64
 
     outputs:
       IMHEX_VERSION: ${{ steps.build.outputs.IMHEX_VERSION }}
@@ -593,8 +593,8 @@ jobs:
           gh actions-cache delete "build-macos-arm64-cache" --confirm || true
 
   macos-arm64-package:
-    runs-on: macos-13
-    name: 🍎 macOS 13 arm64 Packaging
+    runs-on: macos-15-intel
+    name: 🍎 macOS 15 arm64 Packaging
     needs: macos-arm64
 
     env:

README.md

@@ -336,8 +336,8 @@ To use ImHex, the following minimal system requirements need to be met.
 
 - **OS**: 
   - **Windows**: Windows 7 or higher (Windows 10/11 recommended)
-  - **macOS**: macOS 13 (Ventura) or higher, 
-    - Lower versions should still work too, but you'll need to compile ImHex yourself. The release binaries will NOT work due to GitHub not having any macOS 12 or lower CI runners available.
+  - **macOS**: macOS 15 (Sequoia) or higher, 
+    - Lower versions should still work too, but you'll need to compile ImHex yourself. The release binaries will NOT work due to GitHub not having any macOS 15 or lower CI runners available.
     - The macOS build is not signed and will require you to manually allow them in the Security & Privacy settings.
   - **Linux**: "Modern" Linux. The following distributions have official releases available. Other distros are supported through the AppImage, Flatpak and Snap releases.
     - Ubuntu and Debian