Exclude os.FileMode numbers by default

[HTechHQ]

Short summary

Exclude file mode / permissions by default. Similar to the exclusion of other number oriented functions like Date.

As file permissions are typically represented as numbers like in the following example, the linter could ignore that.
My current workaround is a //nolint statement, which makes the code actually less clear to read.

Steps to reproduce the behavior

_, err := os.OpenFile(outputFile, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0o644)

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This is not a bug, but a proposal to change the behaviour and seams to affect all version of go-mnd