Update dependency ubuntu to v26

.github/workflows/app-build.yaml

@@ -13,7 +13,7 @@ permissions:
 jobs:
   build:
     name: Build
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     steps:
       - name: Checkout repository
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1

.github/workflows/app-lint.yaml

@@ -14,7 +14,7 @@ permissions:
 jobs:
   lint:
     name: Lint
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     steps:
       - name: Checkout repository
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1

.github/workflows/app-publish.yaml

@@ -8,7 +8,7 @@ on:
 jobs:
   publish:
     name: Publish
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     if: ${{ contains(github.repository_owner, 'jellyfin') }}
     permissions:
       contents: write

.github/workflows/app-test.yaml

@@ -13,7 +13,7 @@ permissions:
 jobs:
   test:
     name: Test
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     steps:
       - name: Checkout repository
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1

.github/workflows/gradlew-validate.yaml

@@ -14,7 +14,7 @@ permissions:
 jobs:
   validate:
     name: Validate
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     steps:
       - name: Checkout repository
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1

.github/workflows/repo-merge-conflict.yaml

@@ -9,7 +9,7 @@ on:
 jobs:
   triage:
     name: Triage
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     if: ${{ contains(github.repository_owner, 'jellyfin') }}
     steps:
       - uses: eps1lon/actions-label-merge-conflict@0273be72a0bbd58fcd71d0d6c02c209b50d1e5e1 # v3.1.0

.github/workflows/repo-stale.yaml

@@ -12,7 +12,7 @@ permissions:
 jobs:
   triage:
     name: Triage
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     if: ${{ contains(github.repository_owner, 'jellyfin') }}
     steps:
       - uses: actions/stale@4391f3da665fdf50b6810c1a66712fb9ba21aa93 # v11.0.0

.github/workflows/repo-triage.yaml

@@ -9,7 +9,7 @@ on:
 jobs:
   review-add:
     name: Add to reviews project
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-26.04
     if: ${{ contains(github.repository_owner, 'jellyfin') && !github.event.pull_request.draft }}
     steps:
       - name: Add pull request to organization project