remove type errors on postinstall build

[srclosson]

Prior to this change (without being this specific/explicit with the typings) the following errors were returned

src/components/DataSourcePicker/DataSourcePicker.tsx:37:3 - error TS2742: The inferred type of 'dataSourceSrv' cannot be named without a reference to 'ui-enterprise/node_modules/@grafana/runtime'. This is likely not portable. A type annotation is necessary.

37   dataSourceSrv = getDataSourceSrv();
     ~~~~~~~~~~~~~

src/components/DataSourcePicker/DataSourcePicker.tsx:97:3 - error TS2742: The inferred type of 'getDataSourceOptions' cannot be named without a reference to 'ui-enterprise/node_modules/@grafana/data'. This is likely not portable. A type annotation is necessary.

97   getDataSourceOptions() {
     ~~~~~~~~~~~~~~~~~~~~


Found 2 errors.

These changes fix those errors