JetReconstructionConfig: reduce default ghost area to 0.01

[veprbl]

This is also the default in FastJet https://fastjet.fr/repo/doxygen-3.4.2/namespacefastjet_1_1gas.html

Some measurements for a trivial e- reconstruction:

Before:

Elapsed (wall clock) time (h:mm:ss or m:ss): 10:25.74

After:

Elapsed (wall clock) time (h:mm:ss or m:ss): 0:42.34

Closes: #1348 Credit for suggestion goes to @rosijreed

[github-actions[bot]]

Capybara summary for PR 1446

• rec_dis_10x100_minQ2=0_craterlake
• rec_dis_10x100_minQ2=1000_craterlake
• rec_dis_18x275_minQ2=0_craterlake
• rec_dis_18x275_minQ2=1000_craterlake
• rec_dis_5x41_minQ2=0_craterlake
• rec_e_1GeV_20GeV_craterlake
• rec_pi_1GeV_20GeV_craterlake ^{_{Last updated 2024-05-10T06:13-04:00 ed82c4501cae16f86b4b19cde471677e753537d4}}

[epic-capybara]

Successfully created backport PR for v1.13:

• 1447