ci: add missing ref argument for get-go-version

Supports nightly tests.

.github/workflows/nightly-test-integ-peering_commontopo.yml

@@ -39,6 +39,8 @@ jobs:
 
   get-go-version:
     uses: ./.github/workflows/reusable-get-go-version.yml
+    with:
+      ref: ${{ inputs.branch }}
 
   get-envoy-versions:
     uses: ./.github/workflows/reusable-get-envoy-versions.yml

.github/workflows/nightly-test-integrations-1.15.x.yml

@@ -50,8 +50,11 @@ jobs:
   get-go-version:
     needs: [check-ent]
     uses: ./.github/workflows/reusable-get-go-version.yml
+    with:
+      ref: release/1.15.x
 
   get-envoy-versions:
+    needs: [check-ent]
     uses: ./.github/workflows/reusable-get-envoy-versions.yml
     with:
       ref: release/1.15.x

.github/workflows/nightly-test-integrations-1.17.x.yml

@@ -50,8 +50,11 @@ jobs:
   get-go-version:
     needs: [check-ent]
     uses: ./.github/workflows/reusable-get-go-version.yml
+    with:
+      ref: release/1.17.x
 
   get-envoy-versions:
+    needs: [check-ent]
     uses: ./.github/workflows/reusable-get-envoy-versions.yml
     with:
       ref: release/1.17.x

.github/workflows/nightly-test-integrations-1.18.x.yml

@@ -42,6 +42,8 @@ jobs:
 
   get-go-version:
     uses: ./.github/workflows/reusable-get-go-version.yml
+    with:
+      ref: release/1.18.x
 
   get-envoy-versions:
     uses: ./.github/workflows/reusable-get-envoy-versions.yml

.github/workflows/nightly-test-integrations-1.19.x.yml

@@ -42,6 +42,8 @@ jobs:
 
   get-go-version:
     uses: ./.github/workflows/reusable-get-go-version.yml
+    with:
+      ref: release/1.19.x
 
   get-envoy-versions:
     uses: ./.github/workflows/reusable-get-envoy-versions.yml

.github/workflows/reusable-get-go-version.yml

@@ -2,6 +2,12 @@ name: get-go-version
 
 on:
   workflow_call:
+    inputs:
+      ref:
+        description: |
+          The Consul ref/branch (e.g. release/1.18.x) for which to determine the Go version.
+          If not provided, the default actions/checkout value (current ref) is used.
+        type: string
     outputs:
       go-version:
         description: "The Go version detected by this workflow"
@@ -19,6 +25,9 @@ jobs:
       go-version-previous: ${{ steps.get-go-version.outputs.go-version-previous }}
     steps:
       - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b # v4.1.4
+        with:
+          # If not set, will default to current branch.
+          ref: ${{ inputs.ref }}
       - name: Determine Go version
         id: get-go-version
         # We use .go-version as our source of truth for current Go