Upgrade Go to 1.26.0 for building Prometheus

Signed-off-by: Ganesh Vernekar <ganesh.vernekar@reddit.com>

.github/workflows/ci.yml

@@ -16,7 +16,7 @@ jobs:
     container:
       # Whenever the Go version is updated here, .promu.yml
       # should also be updated.
-      image: quay.io/prometheus/golang-builder:1.25-base
+      image: quay.io/prometheus/golang-builder:1.26-base
     steps:
       - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
@@ -34,7 +34,7 @@ jobs:
     name: More Go tests
     runs-on: ubuntu-latest
     container:
-      image: quay.io/prometheus/golang-builder:1.25-base
+      image: quay.io/prometheus/golang-builder:1.26-base
     steps:
       - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
@@ -55,8 +55,6 @@ jobs:
     env:
       # Enforce the Go version.
       GOTOOLCHAIN: local
-      # TODO: remove once 1.25 is the min version.
-      GOEXPERIMENT: synctest
     container:
       # The go version in this image should be N-1 wrt test_go.
       image: quay.io/prometheus/golang-builder:1.25-base
@@ -67,9 +65,6 @@ jobs:
       - run: make build
       # Don't run NPM build; don't run race-detector.
       - run: make test GO_ONLY=1 test-flags=""
-      # TODO: remove once 1.25 is the min version.
-      # ensure we can build without the tag.
-      - run: GOEXPERIMENT="" make build
 
   test_ui:
     name: UI tests
@@ -77,7 +72,7 @@ jobs:
     # Whenever the Go version is updated here, .promu.yml
     # should also be updated.
     container:
-      image: quay.io/prometheus/golang-builder:1.25-base
+      image: quay.io/prometheus/golang-builder:1.26-base
 
     steps:
       - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
@@ -104,7 +99,7 @@ jobs:
           persist-credentials: false
       - uses: actions/setup-go@4dc6199c7b1a012772edbd06daecab0f50c9053c # v6.1.0
         with:
-          go-version: 1.25.x
+          go-version: 1.26.x
       - run: |
           $TestTargets = go list ./... | Where-Object { $_ -NotMatch "(github.com/prometheus/prometheus/config|github.com/prometheus/prometheus/web)"}
           go test $TestTargets -vet=off -v
@@ -116,7 +111,7 @@ jobs:
     # Whenever the Go version is updated here, .promu.yml
     # should also be updated.
     container:
-      image: quay.io/prometheus/golang-builder:1.25-base
+      image: quay.io/prometheus/golang-builder:1.26-base
     steps:
       - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
         with:
@@ -208,7 +203,7 @@ jobs:
     name: Check generated parser
     runs-on: ubuntu-latest
     container:
-      image: quay.io/prometheus/golang-builder:1.25-base
+      image: quay.io/prometheus/golang-builder:1.26-base
     steps:
       - name: Checkout repository
         uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
@@ -231,7 +226,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@4dc6199c7b1a012772edbd06daecab0f50c9053c # v6.1.0
         with:
-          go-version: 1.25.x
+          go-version: 1.26.x
       - name: Install snmp_exporter/generator dependencies
         run: sudo apt-get update && sudo apt-get -y install libsnmp-dev
         if: github.repository == 'prometheus/snmp_exporter'

.github/workflows/fuzzing.yml

@@ -19,7 +19,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@44694675825211faa026b3c33043df3e48a5fa00 # v6.0.0
         with:
-          go-version: 1.25.x
+          go-version: 1.26.x
       - name: Run Fuzzing
         run: go test -fuzz=${{ matrix.fuzz_test }}$ -fuzztime=5m ./util/fuzzing
         continue-on-error: true

.promu.yml

@@ -1,7 +1,7 @@
 go:
     # Whenever the Go version is updated here,
     # .github/workflows should also be updated.
-    version: 1.25
+    version: 1.26
 repository:
     path: github.com/prometheus/prometheus
 build:

scripts/golangci-lint.yml

@@ -30,7 +30,7 @@ jobs:
       - name: Install Go
         uses: actions/setup-go@4dc6199c7b1a012772edbd06daecab0f50c9053c # v6.1.0
         with:
-          go-version: 1.25.x
+          go-version: 1.26.x
       - name: Install snmp_exporter/generator dependencies
         run: sudo apt-get update && sudo apt-get -y install libsnmp-dev
         if: github.repository == 'prometheus/snmp_exporter'