fix unintentional modification of slice in GetSensitiveParameters

[erhancagirici]

Description of your changes

Fixes the prefixes slice variable scope in GetSensitiveParameters()

During resolution of sensitive values in secret ref, #406 introduced support for secret refs from initProvider fields, which introduced a prefixes slice to both check fieldpaths starting with spec.forProvider and spec.initProvider

In #417, prefixes slice was modified in the case of fieldspaths starting with status.atProvider. in response to fix the associated issue.

However, prefixes slice (that is scoped outside of for loop) was being modified in the for loop for the case above, causing remaining iterations to unintentionally operate on modified slice, resulting some secretRef fields to be not resolved into the parameters, thus failing the resource create/update operations

Affected resources are those who have connection details mapping entries include a fieldpath with .status.atProvider followed by some .spec.forProvider and .spec.initProvider entries.

Related crossplane-contrib/provider-upjet-azure#873

I have:

• Read and followed Upjet's contribution process.
• Run make reviewable to ensure this PR is ready for review.
• Added backport release-x.y labels to auto-backport this PR if necessary.

How has this code been tested

Manually and uptest at: crossplane-contrib/provider-upjet-azure#873

[turkenf]

Thank you @erhancagirici, LGTM 🙌