[MNT] change macos runners to macos-latest version (#477)

This PR changes macos runners to `macos-latest` version, as in the other
`sktime` packages.

Author: fkiraly

.github/workflows/test.yml

@@ -69,7 +69,7 @@ jobs:
       fail-fast: false
       matrix:
         python-version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
-        os: [ubuntu-latest, windows-latest, macOS-13]
+        os: [ubuntu-latest, windows-latest, macOS-latest]
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
@@ -108,7 +108,7 @@ jobs:
       fail-fast: false
       matrix:
         python-version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
-        os: [ubuntu-latest, windows-latest, macOS-13]
+        os: [ubuntu-latest, windows-latest, macOS-latest]
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4

.github/workflows/wheels.yml

@@ -34,7 +34,7 @@ jobs:
     strategy:
       fail-fast: false  # to not fail all combinations if just one fail
       matrix:
-        os: [ubuntu-latest, macOS-13]
+        os: [ubuntu-latest, macOS-latest]
         python-version: ["3.9", "3.10", "3.11", "3.12", "3.13"]
 
     steps: