fix: when includeComponentInTag is false, there should be no component in the branch name

[sofisl]

I was investigating why release-please did not open a PR here: googleapis/gax-nodejs#1553

The CLI fails with the warning:

⚠ PR component: undefined does not match configured component: google-gax

(here):

release-please/src/strategies/base.ts

Line 615 in 72b0ab3

`PR component: ${branchName.component} does not match configured component: ${branchComponent}`

That is true, since the branch does not contain the component:

It kind of makes sense that the branchName wouldn't contain the component, since we're setting that in the config (https://github.com/googleapis/gax-nodejs/blob/c65cee0fd56ff2682d5cfb91ca639ee98e93f568/release-please-config.json#L11)

We can mirror what getComponent has, here:

release-please/src/strategies/base.ts

Line 163 in 72b0ab3

if (!this.includeComponentInTag) {

in getBranchComponent