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

npm ci、npm run build:styling、tsc -b -f を使用して報告を再現します。109 行目と 119 行目の packages/linear-progress/src/mwc-linear-progress-base.ts を調査し、インデックス付き CSS スタイル割り当てで TS2322 が発生する理由を追跡します。報告されたエラーが、ビルドコマンドを壊すことなく解消されれば完了です。