chore: remove obsolete workflow 'Bump Go'

Superseded by dependabot

.github/versions/go

@@ -1 +0,0 @@
-1.14.3

.github/workflows/bump-go.yml

@@ -1,28 +0,0 @@
-name: Bump Go
-on:
-  schedule:
-    - cron: 00 7 * * *
-  push:
-    branches:
-      - master
-jobs:
-  bump-go:
-    runs-on: ubuntu-20.04
-    steps:
-      - name: Clone current repo
-        uses: actions/checkout@v2
-
-      - name: Ensure Go is up-to-date
-        id: bump-go
-        uses: BBVA/bump-go@main
-        with:
-          go-version-path: .github/versions/go
-
-      - name: Create pull request
-        uses: peter-evans/create-pull-request@v3
-        with:
-          author: GitHub <noreply@github.com>
-          title: "chore: bump Go version"
-          commit-message: Bump Go to version ${{ steps.bump-go.outputs.go-version }}
-          branch: bump-go/patch
-          delete-branch: true