.github/workflows: stop if unit tests fail

continue-on-error was set true to keep testing, but
it obviously makes the test failure difficult to notice.
Fail hard.

Fixes golang/vscode-go#289

Change-Id: Ib872a99a97ffc008bac98149d2ed3cc3a9989087
GitHub-Last-Rev: 53c971af2d8a529073485925e283d66a7a030d33
GitHub-Pull-Request: golang/vscode-go#295
Reviewed-on: https://go-review.googlesource.com/c/vscode-go/+/241129
Reviewed-by: Rebecca Stambler <rstambler@golang.org>
diff --git a/.github/workflows/release-nightly.yml b/.github/workflows/release-nightly.yml
index a04eaae..8110c20 100644
--- a/.github/workflows/release-nightly.yml
+++ b/.github/workflows/release-nightly.yml
@@ -70,7 +70,6 @@
 
       - name: Run unit tests
         run: npm run unit-test
-        continue-on-error: true
 
       - name: Run tests
         uses: GabrielBB/xvfb-action@v1.0
diff --git a/.github/workflows/test-long.yml b/.github/workflows/test-long.yml
index 1b5f75e..6fcbbd7 100644
--- a/.github/workflows/test-long.yml
+++ b/.github/workflows/test-long.yml
@@ -69,7 +69,6 @@
       
       - name: Run unit tests
         run: npm run unit-test
-        continue-on-error: true
         
       - name: Run tests
         uses: GabrielBB/xvfb-action@v1.0
diff --git a/.github/workflows/test-smoke.yml b/.github/workflows/test-smoke.yml
index 96e517f..150b21a 100644
--- a/.github/workflows/test-smoke.yml
+++ b/.github/workflows/test-smoke.yml
@@ -65,7 +65,6 @@
       
       - name: Run unit tests
         run: npm run unit-test
-        continue-on-error: true
         
       - name: Run tests
         uses: GabrielBB/xvfb-action@v1.0