Revert "add new CI step: "setup upstream remote""

This reverts commit 4454fa9.

(cherry picked from commit 395fb70)

Author: pietroalbini

Diff for: .github/workflows/ci.yml

@@ -130,9 +130,6 @@ jobs:
           # which then uses log commands to actually set them.
           EXTRA_VARIABLES: ${{ toJson(matrix.env) }}
 
-      - name: setup upstream remote
-        run: src/ci/scripts/setup-upstream-remote.sh
-
       - name: ensure the channel matches the target branch
         run: src/ci/scripts/verify-channel.sh
 

Diff for: src/ci/scripts/setup-upstream-remote.sh

@@ -137,15 +137,3 @@ function releaseChannel {
         echo $RUST_CI_OVERRIDE_RELEASE_CHANNEL
     fi
 }
-
-# Parse values from src/stage0 file by key
-function parse_stage0_file_by_key {
-    local key="$1"
-    local file="$ci_dir/../stage0"
-    local value=$(awk -F= '{a[$1]=$2} END {print(a["'$key'"])}' $file)
-    if [ -z "$value" ]; then
-        echo "ERROR: Key '$key' not found in '$file'."
-        exit 1
-    fi
-    echo "$value"
-}