feat(setup-wizard): Prefill project and team (#85920)

Pre-fill project and team input if there is only one available option.

- closes #85529

Author: ArthurKnaus

static/app/views/setupWizard/wizardProjectSelection.tsx

@@ -1,4 +1,4 @@
-import {Fragment, useCallback, useMemo, useState} from 'react';
+import {Fragment, useCallback, useEffect, useMemo, useState} from 'react';
 import styled from '@emotion/styled';
 
 import {addErrorMessage} from 'sentry/actionCreators/indicator';
@@ -130,6 +130,22 @@ export function WizardProjectSelection({
   const {options: cachedProjectOptions, clear: clearProjectOptions} =
     useCompactSelectOptionsCache(projectOptions);
 
+  // Set the selected project to the first option if there is only one
+  useEffect(() => {
+    // We need to check the cached options as they hold all options that were fetched for the org
+    // and not just the options that match the search query
+    if (cachedProjectOptions.length === 1) {
+      setSelectedProjectId(cachedProjectOptions[0]!.value);
+    }
+  }, [cachedProjectOptions]);
+
+  // Set the selected team to the first team if there is only one
+  useEffect(() => {
+    if (teamsRequest.data && teamsRequest.data.length === 1) {
+      setNewProjectTeam(teamsRequest.data[0]!.slug);
+    }
+  }, [teamsRequest.data]);
+
   // As the cache hook sorts the options by value, we need to sort them afterwards
   const sortedProjectOptions = useMemo(
     () =>