Revert ".github/workflows: run Long Tests with go1.16 rc1"

This reverts commit 32a9f15e3eb105df3be72dbf7d3df45446218daa.

Reason for revert: this config is embarrassingly broken and our tests are not ready for go1.16 testing

Change-Id: I0a01a1042b98eed685617b4950c669017972a234
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/291049
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
Trust: Hyang-Ah Hana Kim <hyangah@gmail.com>
diff --git a/.github/workflows/tip-test-long.yml b/.github/workflows/tip-test-long.yml
deleted file mode 100644
index 6cebfc5..0000000
--- a/.github/workflows/tip-test-long.yml
+++ /dev/null
@@ -1,73 +0,0 @@
-name: Long Tests (1.16)
-
-on:
-  push:
-    branches-ignore:
-      - 'latest'
-      - 'upstream'
-
-jobs:
-  build:
-    name: ${{ matrix.os }} ${{ matrix.version }}
-    runs-on: ${{ matrix.os }}
-
-    # Not containing 'SKIP CI' in the commit message AND
-    # (Either non-Windows OR triggered on 'push' (if triggered by 'pull_request', github.base_ref is not empty)
-    if: github.repository == 'golang/vscode-go' && !contains(github.event.head_commit.message, 'SKIP CI')
-    timeout-minutes: 20
-    strategy:
-      fail-fast: false
-      matrix:
-        os: [ubuntu-latest]
-        version: ['stable']
-
-    steps:
-      - name: Clone repository
-        uses: actions/checkout@v2
-
-      - name: Setup Node
-        uses: actions/setup-node@v1
-        with:
-          node-version: '10.x'
-
-      - name: Setup Go
-        uses: actions/setup-go@v2
-        with:
-         go-version: '1.16.0-rc1'
-         stable: stable: '!contains(${{ matrix.go }}, "beta") && !contains(${{ matrix.go }}, "rc")
-
-      - name: Install dependencies
-        run: npm ci
-      
-      - name: Compile
-        run: npm run vscode:prepublish
-
-      - name: Install Go tools (Modules mode)
-        run: |
-            go version
-            go get github.com/acroca/go-symbols
-            go get github.com/davidrjenni/reftools/cmd/fillstruct
-            go get github.com/haya14busa/goplay/cmd/goplay
-            go get github.com/mdempsky/gocode
-            go get github.com/sqs/goreturns
-            go get github.com/uudashr/gopkgs/v2/cmd/gopkgs
-            go get github.com/zmb3/gogetdoc
-            go get golang.org/x/lint/golint
-            go get golang.org/x/tools/cmd/gorename
-            go get golang.org/x/tools/gopls
-            go get github.com/cweill/gotests/...
-            go get github.com/rogpeppe/godef
-            go get github.com/ramya-rao-a/go-outline
-            go get github.com/go-delve/delve/cmd/dlv
-        env:
-          GO111MODULE: on   
-          
-      - name: Run unit tests
-        run: npm run unit-test
-        
-      - name: Run tests
-        uses: GabrielBB/xvfb-action@v1.0
-        with:
-          run: npm run test
-        env:
-          CODE_VERSION: ${{ matrix.version }}