chore(shorebird_cli): remove unnecessary trailing / from storage url (#343)

packages/shorebird_cli/lib/src/shorebird_process.dart

@@ -106,7 +106,7 @@ class ShorebirdProcess {
     if (executable == 'flutter') {
       // If this ever changes we also need to update the `shorebird` shell
       // wrapper which downloads runs Flutter to fetch artifacts the first time.
-      return {'FLUTTER_STORAGE_BASE_URL': 'https://download.shorebird.dev/'};
+      return {'FLUTTER_STORAGE_BASE_URL': 'https://download.shorebird.dev'};
     }
 
     return {};

packages/shorebird_cli/test/src/shorebird_process_test.dart

@@ -12,6 +12,10 @@ class _MockProcessWrapper extends Mock implements ProcessWrapper {}
 
 void main() {
   group('ShorebirdProcess', () {
+    const flutterStorageBaseUrlEnv = {
+      'FLUTTER_STORAGE_BASE_URL': 'https://download.shorebird.dev',
+    };
+
     late ProcessWrapper processWrapper;
     late Process startProcess;
     late ProcessResult runProcessResult;
@@ -79,9 +83,7 @@ void main() {
             any(that: contains('bin/cache/flutter/bin/flutter')),
             ['--version'],
             runInShell: true,
-            environment: {
-              'FLUTTER_STORAGE_BASE_URL': 'https://download.shorebird.dev/',
-            },
+            environment: flutterStorageBaseUrlEnv,
             workingDirectory: '~',
           ),
         ).called(1);
@@ -202,9 +204,7 @@ void main() {
             any(that: contains('bin/cache/flutter/bin/flutter')),
             ['run'],
             runInShell: true,
-            environment: {
-              'FLUTTER_STORAGE_BASE_URL': 'https://download.shorebird.dev/',
-            },
+            environment: flutterStorageBaseUrlEnv,
           ),
         ).called(1);
       });
@@ -245,7 +245,7 @@ void main() {
           runInShell: true,
           environment: {
             'ENV_VAR': 'asdfasdf',
-            'FLUTTER_STORAGE_BASE_URL': 'https://download.shorebird.dev/',
+            ...flutterStorageBaseUrlEnv,
           },
         ),
       ).called(1);

third_party/flutter/bin/internal/shared.sh

@@ -20,7 +20,7 @@ function update_flutter {
   SHOREBIRD_ENGINE_VERSION=`cat "$FLUTTER_PATH/bin/internal/engine.version"`
   echo "Shorebird Engine • revision $SHOREBIRD_ENGINE_VERSION"
   # Install Shorebird Flutter Artifacts
-  FLUTTER_STORAGE_BASE_URL=https://download.shorebird.dev/ $FLUTTER_PATH/bin/flutter --version  
+  FLUTTER_STORAGE_BASE_URL=https://download.shorebird.dev $FLUTTER_PATH/bin/flutter --version  
 }
 
 function pub_upgrade_with_retry {