fix: restrict isNumeric() to ASCII digits to prevent NumberFormatExceptionRefactor digit validation logic in MavenArchiver

[HarshMehta112]

Fixes : #365

Problem

The isNumeric() method currently uses Character.isDigit(), which returns true for many non-ASCII Unicode digits (such as Arabic-Indic ٠١٢٣, Bengali ০১২৩, and Devanagari ०१२३).

When parseBuildOutputTimestamp() receives one of these values through project.build.outputTimestamp or SOURCE_DATE_EPOCH, isNumeric() incorrectly treats it as a valid numeric string. The value is then passed to Long.parseLong() (around line 697), which only accepts ASCII digits (0–9) and throws a NumberFormatException.

Since the method only catches DateTimeParseException (around line 708), the NumberFormatException propagates uncaught, causing archive creation to fail with an unhelpful error message.

Fix

Replace the use of Character.isDigit() with an explicit ASCII digit check:

c >= '0' && c <= '9'

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[elharo]

personally I prefer

c >= '0' && c <= '9'

but either way is fine

[github-actions]

@elharo Please assign appropriate label to PR according to the type of change.