packageVerificationCode uses upper case hex, should use lower case.

[ddillard]

As an example, in this SBOM there is the following:

"name": "SAG-PM.msi",
			"packageVerificationCode": {
				"packageVerificationCodeValue": "2CC97F5B3328F5934224E3090E2B80DCFE3575B4"
			},

However, the SPDX 2.3 spec states the value should be a "Single line of text with 160 bit binary represented as 40 lowercase hexadecimal digits." (emphasis is mine)