Use Go version specified by go directive for "Compare Performance" build

The Go version compatibility at one ref may be different than at another. This was already managed for very old versions
of the project, but there is a need for such a system even for newer versions.

Author: per1234

.github/workflows/compare-performance.yml

@@ -1,8 +1,6 @@
 name: Compare Performance
 
 env:
-  # See: https://github.com/actions/setup-go/tree/v2#readme
-  GO_VERSION: "1.16"
   REPORTS_ARTIFACT_NAME: reports
 
 # See: https://docs.github.com/en/free-pro-team@latest/actions/reference/events-that-trigger-workflows
@@ -118,7 +116,8 @@ jobs:
         id: go-version
         run: |
           if [[ -f "go.mod" ]]; then
-            USE_GO_VERSION="${{ env.GO_VERSION }}"
+            # This will use the runner's pre-installed Go
+            USE_GO_VERSION="$(go mod edit -json | jq --raw-output '.Go')"
           else
             # Dependency installation for old engine versions fails when not in GOPATH mode. Go <1.16 uses
             # GO111MODULE=auto by default, meaning it will use GOPATH mode. Old Go versions were used by the old engine