Bug: gas_price suggestions are too low causing transactions to fail

**Describe the bug**

Bounty payout calls are being sent with a suggested `gas_price` which is too low (5gwei).

Since the adoption of EIP 1559, we should avoid suggesting a `gas_price` and let the users wallet discover this value itself.

This likely also means that any of our gas price aware contract calls site-wide are being sent with the wrong `gas_price` too, additionally, the fact that the page recommends 5gwei (the default amount) would suggest that the `sync_gas_fees` mgmt command is also broken since EIP 1559.

**Definition of done**

GIVEN I am a bounty funder looking to pay out a contributor on a specific bounty
WHEN I click "payout"
AND it activates metamask
THEN the suggested gas fee is from Metamask, not "site suggested".

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GIVEN I am a Gitcoin user looking to tip another Gitcoin user
WHEN I click "send tip"
AND it activates metamask
THEN the suggested gas fee is from Metamask, not "site suggested".

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GIVEN I am a Gitcoin Grant contributor looking to checkout my cart on the checkout page
WHEN I click "standard checkout"
AND it activates metamask
THEN the suggested gas fee is from Metamask, not "site suggested".