Changing issue assignees has bad progress reporting (#6877)

Fixes #6865

Author: alexr00

src/github/issueOverview.ts

@@ -316,6 +316,7 @@ export class IssueOverviewPanel<TItem extends IssueModel = IssueModel> extends W
 			const hidePromise = asPromise<void>(quickPick.onDidHide);
 			const labelsToAdd = await Promise.race<readonly vscode.QuickPickItem[] | void>([acceptPromise, hidePromise]);
 			quickPick.busy = true;
+			quickPick.enabled = false;
 
 			if (labelsToAdd) {
 				await this._item.setLabels(labelsToAdd.map(r => r.label));
@@ -393,6 +394,7 @@ export class IssueOverviewPanel<TItem extends IssueModel = IssueModel> extends W
 			const hidePromise = asPromise<void>(quickPick.onDidHide);
 			const allAssignees = await Promise.race<(vscode.QuickPickItem & { user: IAccount })[] | void>([acceptPromise, hidePromise]);
 			quickPick.busy = true;
+			quickPick.enabled = false;
 
 			if (allAssignees) {
 				const newAssignees: IAccount[] = allAssignees.map(item => item.user);

src/github/pullRequestOverview.ts

@@ -387,6 +387,7 @@ export class PullRequestOverviewPanel extends IssueOverviewPanel<PullRequestMode
 			const hidePromise = asPromise<void>(quickPick.onDidHide);
 			const allReviewers = await Promise.race<(IAccount | ITeam)[] | void>([acceptPromise, hidePromise]);
 			quickPick.busy = true;
+			quickPick.enabled = false;
 
 			if (allReviewers) {
 				const newUserReviewers: IAccount[] = [];