chore(deps): update dependency go to 1.26

Author: renovate[bot]

.github/workflows/internal_tests.yaml

@@ -21,7 +21,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v6
         with:
-          go-version: 1.25
+          go-version: 1.26
 
       - name: Ensure No Formatting Changes
         run: |

.github/workflows/planner_integration.yaml

@@ -37,7 +37,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v6
         with:
-          go-version: 1.25
+          go-version: 1.26
 
       - name: Wait for rabbitmq
         run: |

.github/workflows/webhook_gateway_integration.yaml

@@ -37,7 +37,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v6
         with:
-          go-version: 1.25
+          go-version: 1.26
 
       - name: Wait for rabbitmq
         run: |