Update dependency go to 1.26

Signed-off-by: red-hat-konflux <126015336+red-hat-konflux[bot]@users.noreply.github.com>

Author: red-hat-konflux[bot]

.github/workflows/build-agent-alertmanager.yml

@@ -15,7 +15,7 @@ jobs:
       - uses: actions/checkout@v5
       - uses: actions/setup-go@v6
         with:
-          go-version: '1.25'
+          go-version: '1.26'
       - name: Build
         working-directory: tools/agents/agent-alertmanager
         run: CGO_ENABLED=0 go build -ldflags="-s -w" -o agent-alertmanager .

.github/workflows/build-agent-splunk.yml

@@ -13,7 +13,7 @@ jobs:
       - uses: actions/checkout@v5
       - uses: actions/setup-go@v6
         with:
-          go-version: '1.25'
+          go-version: '1.26'
       - name: Build
         working-directory: tools/agents/agent-splunk
         run: CGO_ENABLED=0 go build -o agent-splunk .