CI: clean up workflow names

.github/workflows/main.yml

@@ -1,4 +1,4 @@
-name: CI
+name: Merge queue and try
 
 on:
   # Triggers the workflow on push events but only for the master branch

.github/workflows/nightly-rust.yml

@@ -1,4 +1,4 @@
-name: Nightly rustc build
+name: Test with nightly rustc
 
 on:
   schedule:

.github/workflows/nightly.yml

@@ -1,4 +1,4 @@
-name: Nightly builds
+name: Release nightly
 
 on:
   schedule:

.github/workflows/pull-request.yml

@@ -1,4 +1,4 @@
-name: Basic cross-platform builds and checks
+name: Pull request
 on:
   pull_request:
     branches: ["**"]

.github/workflows/test-upstream-wpt-changes.yml

@@ -1,4 +1,4 @@
-name: Test changes to upstream-wpt-changes
+name: WPT exporter test
 on:
   pull_request:
     branches: ["**"]

.github/workflows/upstream-wpt-changes.yml

@@ -1,5 +1,5 @@
 # Disabled until the previous bot is turned off.
-#name: Upstream Web Platform Test changes
+#name: WPT export
 #on:
 #  pull_request:
 #    types: ['opened', 'synchronize', 'reopened', 'edited', 'closed']

.github/workflows/wpt-nightly.yml

@@ -1,4 +1,4 @@
-name: Synchronize WPT Nightly
+name: WPT import
 
 on:
   schedule: