New error: Type 'string' is not assignable to type 'string & ...'

https://github.com/material-components/material-components-web-components/blob/b1862998d80f4b0b917c817e6efde15a2504d8da/packages/linear-progress/src/mwc-linear-progress-base.ts#L109 ``` packages/linear-progress/src/mwc-linear-progress-base.ts:109:9 - error TS2322: Type 'string' is not assignable to type 'string & ((property: string) => string) & ((property: string) => string) & ((index: number) => string) & ((property: string) => string) & ((property: string, value: string | null, priority?: string | undefined) => void)'. Type 'string' is not assignable to type '(property: string) => string'. 109 this.bufferElement ~~~~~~~~~~~~~~~~~~ 110 .style[property as Exclude<keyof CSSStyleDeclaration, 'length'|'parentRule'>] = ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ``` https://github.com/material-components/material-components-web-components/blob/b1862998d80f4b0b917c817e6efde15a2504d8da/packages/linear-progress/src/mwc-linear-progress-base.ts#L119 ``` packages/linear-progress/src/mwc-linear-progress-base.ts:119:9 - error TS2322: Type 'string' is not assignable to type 'string & ((property: string) => string) & ((property: string) => string) & ((index: number) => string) & ((property: string) => string) & ((property: string, value: string | null, priority?: string | undefined) => void)'. Type 'string' is not assignable to type '(property: string) => string'. 119 this.primaryBar ~~~~~~~~~~~~~~~ 120 .style[property as Exclude<keyof CSSStyleDeclaration, 'length'|'parentRule'>] = ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ``` To repro: 1) `npm ci` 2) `npm run build:styling` 3) `tsc -b -f`