Add support for Cyclonedx specVersion 1.7 #136

Description

parlay doesn't currently support CycloneDX 1.7 SBOMs. The highest supported version is 1.6 (added in v0.5.1).

I run into this issue when I use the cyclonedx-cli and it updates my merged sbom to "specVersion": "1.7". When I manually change the specVersion` to anything below 1.7, parlay will work

10:38PM FTL Failed to read SBOM input error="could not decode input: invalid specification version"
Error: Process completed with exit code 1.

I believe this is where the issue would be fixed:
format.go

• add new constants:

SBOMFormatCycloneDX1_7JSON = SBOMFormat("CycloneDX 1.7 JSON")
SBOMFormatCycloneDX1_7XML = SBOMFormat("CycloneDX 1.7 XML")

cyclonedx.go

• add decode/encode functions for 1.7 (same pattern as 1.5/1.6).

decode.go

• update identifySBOMFormat to detect specVersion: 1.7 and add the corresponding cases to the switch in DecodeSBOMDocument.

github.com/CycloneDX/cyclonedx-go v0.9.2 already includes SpecVersion1_7, so no dependency bump needed.