wolfictl check update github release checker should support full semver for pre-releases

[pnasrat]

For example Python PEP 440 uses pre-release identfiers including a and b

These are compatible with semver but not excluded when wolfictl check update is run

Currently the githubrelease checker uses []string{"alpha", "beta", "rc", "pre"}

wolfictl/pkg/update/githubReleases.go

Line 559 in dc84d81

invalid := []string{"alpha", "beta", "rc", "pre"}

Semver defines pre-releases as

A pre-release version MAY be denoted by appending a hyphen and a series of dot separated identifiers immediately following the patch version. Identifiers MUST comprise only ASCII alphanumerics and hyphens [0-9A-Za-z-]. Identifiers MUST NOT be empty. Numeric identifiers MUST NOT include leading zeroes.

• https://semver.org/spec/v2.0.0.html#spec-item-9
• https://semver.org/spec/v2.0.0.html#backusnaur-form-grammar-for-valid-semver-versions

[luhring]

cc: @rawlingsj