Update licensing information

Dependencies

• [2] 576M5IPA Add type for raw price specs

Change contents

• edit in beancount/price-spec/src/lib.rs at line 1
  [2.809]

  [2.810]
  + // SPDX-FileCopyrightText: 2024 Markus Haug (Korrat)

  + //

  + // SPDX-License-Identifier: EUPL-1.2

  +
• edit in beancount/price-spec/Cargo.toml at line 1
  [2.1585]

  [2.1586]
  + # SPDX-FileCopyrightText: 2024 Markus Haug (Korrat)

  + #

  + # SPDX-License-Identifier: EUPL-1.2

  +