Replace hardcoded github.com/gitlab.com checks with detectPlatform()

[rarkins]

Describe the proposed change(s).

We have some inconsistency in our code where sometimes we check if a host is e.g. github.com or includes the string "github" in its hostname, and other times we have a more sophisticated check using detectPlatform(). We should do a code review for remaining hardcoded checks and see which can be replaced with detectPlatform().

[RahulGautamSingh]

I could only find this one instance where we can directly use detectPlatform

renovate/lib/workers/repository/update/pr/changelog/github/source.ts

Line 40 in 632e8a5

protected override hasValidToken(config: BranchUpgradeConfig): {

Apart from this I found the following 4 instances where it seems we can use the detectPlatform function but cannot/should not :

1. renovate/lib/modules/manager/bazel/rules/http.ts

   Line 102 in 632e8a5

   export function parseArchiveUrl(

2. renovate/lib/modules/manager/homebrew/extract.ts

   Line 59 in 632e8a5

   export function parseUrlPath(

3. renovate/lib/modules/manager/swift/extract.ts

   Line 121 in 632e8a5

   function getDepName(url: string | null): string | null {

(In the above 3 cases, we should not use detectPlatform because parseUrl is already called within the fns and the other fields returned from the parseUrl fn are also used in them. If we use detectPlatform just for the url matching then we will be repeating similar logic as detectPlatform calls parseUrl too.)

---

4. renovate/lib/modules/manager/pre-commit/extract.ts

   Lines 31 to 37 in 632e8a5

   	if (hostname === 'github.com' || detectPlatform(repository) === 'github') {
   	logger.debug({ repository, hostname }, 'Found github dependency');
   	return { datasource: GithubTagsDatasource.id };
   	}
   	if (hostname === 'gitlab.com') {
   	logger.debug({ repository, hostname }, 'Found gitlab dependency');
   	return { datasource: GitlabTagsDatasource.id };

(We cannot as its only the hostname which is being compared and not the full url )